Breathable Paints Explained


Adam Brown

FdSc Sustainable Construction BSc, Building Surveying & the Environment

About the author

Adam has 10+ years of expertise in building conservation & breathable materials.

What are breathable paints?

The term breathable is everywhere, from nail polish through to clothing. The dictionary defines breathable under two definitions:

1.   Suitable or pleasant for breathing
2.   Permitting air to pass through

This is an extremely varied definition, on the one hand it means that air or moisture can pass through a material, on the other it means that a material is safe for humans to use. The wide scope and interpretation of this term has led to confusion, what exactly constitutes a breathable paint?

For building physics we class a breathable paint as a material that will allow the water vapour to permeate, travel or transfer through itself. The basic premise of a truly breathable paint is its ability to allow water vapour to evaporate from the surface and not prevent this transfer to be slowed or stopped entirely. View our full range of breathable paints.

We have defined a breathable paint in its basic form but we are still left with a serious issue.  A lot of paints on today’s market state to be breathable but  how do we know what is best? How breathable are they? As they state they are breathable does this mean safe to breath or they allow moisture to pass through them?

There is no defined European Standard as to what constitutes breathability and there are at least 8 different ways to measure the breathability of a material. Until the industry adopts a defined standard this will always be an issue, however when it comes to paint the most accepted and adopted standard is SD Value, it helps that it is probably the easiest to understand, interpret and compare.

SD Value is a German method, although it used throughout Europe, and it stands for steam diffusion or air layer equivalence. It is a measure of how much of a barrier a paint coating is to water vapour and how easily the vapour can pass through this barrier, it is measured in meters. The lower the SD Value means that more moisture is able to pass through, the higher the SD Value, the lower the moisture transfer, and less moisture can pass through.

A truly breathable paint should have an SD Value ranging from 0.01 to 0.05. This equates to moisture having to travel 1cm to 5cm to pass through the paint, meaning it has very little resistance and can pass freely without being slowed or stopped. Conventional masonry paints will likely have an SD Value of 1 or above. This equates to moisture having to travel through the equivalent of 1 metre of air to escape.

The vast majority of paints can technically be classed as “breathable”, as they will eventually allow some moisture to escape. However, it is the rate of transfer or the distance which constitutes a truly breathable paint.

If you were to look at one of our paints you will always be able to find the SD Value and this is regardless of the brand, in fact if you look at competitors’ products they usually always state the SD Value of their paints, because they know they are offering a truly breathable paint. However, if you were to look at a conventional emulsion or masonry paint that states it is breathable, there is no SD Value to be seen. This can usually be taken as a clear sign that this paint will not allow for the free passage of moisture, otherwise the SD Value would be there. Most “breathable” paints that do not state SD Value usually fall in their class of the first definition of breathability; they are suitable to be breathed, meaning they won’t necessarily harm us, or they are technically breathable, but simply won’t allow high levels of moisture to transfer freely.

Join us for a free webinar on Breathable Paints and Maintenance

Why use breathable paints for historic buildings?

Older buildings are fairly simple in construction, they usually comprise of thick and solid walls, with no cavity. The result of this construction method means that moisture will always be, in some form, present within the building fabric. The original material (Lime Mortar made from Lime Putty) used to create these buildings were relatively simple too; they were softer than the host material (i.e. stone) and they allowed moisture to escape and not become trapped. View our range of breathable lime mortars, renders and plasters.

Damp is commonly found in older buildings. Up until recently it was (and unfortunately by some it still is) believed that the only way to eradicate this issue was to waterproof the entire building with a waterproof coating such as modern masonry paint or by injecting damp proof courses with the aim to stop water penetrating the building. Whilst this offered a temporary solution it was and is still not the answer, with the majority of these applications ultimately failing.

A historic building with render and stone.

One of the main reasons for this failure is that a building can undergo significant movement, both structurally and thermally. Once a crack appears water can penetrate the crack and be held within the wall behind the non-breathable or waterproof coating, which can include cement and paint. A secondary issue with cracking is during the winter or colder months, as water freezes it has an expansion rate of roughly 9% per freeze. As this freeze and thaw cycle is repeated when we reach certain temperatures, the cracks are able to increase and widen in size, which allows further water to ingress with no means of escape.

A build-up of moisture can lead to damp within the walls which may cause ‘blistering’ and ‘bubbling’ of the paint where the water is trying to escape. This is referred to as hydraulic pressure. In more serious cases the render may be ‘blown’ or forced off by the pressure of the trapped water.

Water that is trapped within a wall can lead to serious deterioration of the building fabric. Any non-breathable paint applied to the building will act like a film around its surface. If you imagine wrapping your walls and ceilings in cling film, this will stop the moisture from going in and out but will trap it and the water will build up within the surface. This is where the term “film-forming” paint comes from as it seals the building and stops the building from breathing and allowing moisture out of the walls.

The reason that modern paints such as emulsions and masonry paints are classified as film forming is due to the chemicals that are used, which create a plastic like layer, enabling them to sit on the surface of a wall or ceiling. If your looking to remove paint, see our guide on paint stripping.

Get started with painting stripping with this handy guide

This leads us back to the issue with defining breathable paints: You can wrap your face in cling film and poke a hole where your mouth is, you can still breathe, but you aren’t going to live very long. To put it simply, the most appropriate paint for historic fabric is one that has a low SD Value.

Why use breathable paint for contemporary and new build construction?

Paints are everywhere, both internally and externally. Most modern paints are comprised of pigments, binders and solvents, however the majority of these components are derived from petrochemicals. The use of petrochemicals has a negative impact on both our health and environment. The use of crude oil to create these materials can lead to the creation of harmful toxic waste.

Modern building with breathable mineral paint.

In 1989 the World Health Organisation reported that painting is an occupation that is classified as carcinogenic due to the extensive use of chemicals that are contained within paints. Further studies have shown the indoor air environment can be 10 times more polluted than the external environment, which is again caused by the extensive chemical additions found in materials such as modern paint. We spend up to 80% of our lives inside buildings, where up to 90% of the internal surface can be covered in some form of petrochemical coating. Due to the chemical additions contained within these paints they become very wasteful, in some cases these materials can produce up to 10 times their weight in waste. In the UK 385 million tonne of paint is sold yearly. A further issue is that the chemical additions make recycling the paint very difficult, with the majority of discarded paint being sent to landfill.

We only stock naturally produced paints, that have minimal to no chemical additions depending on the type and brand. This allows us to supply paints that have no detrimental impact on the environment, the applicator or the end user.

Breathable paints are often seen as something that are only suitable for older building, this is not the case. Breathability is also an important factor within modern buildings. By using a breathable paint internally, you can help regulate the internal environment and air quality. Breathable paints can absorb moisture and release it again, meaning when humidity is high the paint can take moisture from the air and release it back when the humidity drops, which helps maintain a healthy environment and acts like a natural dehumidifier.

Types of breathable paints?

We offer all types of paints for both internal and external applications. The most commonly known is limewash which consists of burnt limestone and water. When applied to a porous wall it soaks in, absorbs CO2 and reverts back to limestone. Limewash makes a superb internal and external coating and can be coloured using pigments.

Shop our collection of traditional limewash

As a derivative of limewash we also supply Lime Paint which comes in a powder form ready to mix with water. Lime paint can be supplied in 19 different colours and although it contains around 3% acrylic to aid dusting and adhesion it still retains a low SD value and is highly suited to lime rendered buildings both internal and external.

Beeck Mineral Silicate Paints were developed at the end of the 19th century and, as with limewash, the mineral paints soak into the background and bond to it. Where they differ is that limewash generally bonds to the calcium in the background whereas mineral paints form a strong chemical bond with the silica sand in the stone or render.

It is well known what a strong and stable element silica is and it has been widely used in building due to these attributes. This silica bond makes the paints far more durable than limewash or lime paint, leaving the paint attached to the substrate. The way the paint bonds to the surface also gives it extreme durability as the chemical bond achieved means that it cannot be stripped by paint strippers.

Externally the Beeck Mineral Paints contain a hydrophobe, which repels water from the surface, without having any impact on the breathability of the coating, which adds further protection for the underlying surface.

Mineral paints also offer much greater longevity compared to limewash and lime paint due to the bond with the surface, they are also non-flammable along with many other benefits depending on what type of mineral paint that is used. They can be mixed to over 300 colours.

We are stockists for Earthborn who supply a range of breathable claypaints and emulsions.

Most Popular Breathable Paints

For most applications we recommend the use of Beeck Mineral Paints as they are by far the most durable breathable paints. Want more information on Beeck? See our guide on Beeck Mineral Paint.

A few colours from the Beeck Mineral Paint range.

In short, for internal applications we recommend Beeck. Beeck Maxil Pro is our is our go-to internal paint, easy to apply and available in a wide range of colours.

For exterior applications, in particular for facades looking for protection from the elements, we recommend Beeck Renosil is our go-to external paint. Renosil can be applied onto most backgrounds. (If applying onto bare lime you may want to consider Beeckosil).

The information provided by Cornish Lime is for informational purposes only and does not amount to a specification. Every project is unique, so please consult a professional before undertaking a project. Use of this site and reliance on any information on the site is solely at your own risk.

Related products


Many paints may indicate that they are breathable, but it’s good to check to what degree. To do so, check the paint’s SD value. The SD or Steam Diffusion value measures how resistant a coating is to allowing moisture to pass through. The lower the SD value, the less resistance and more breathability. A genuinely breathable paint will have an SD Value of 0.01 to 0.05.

For most applications, we recommend the use of Beeck Mineral Paints as they are by far the most durable breathable paints.

A breathable paint can be beneficial for walls susceptible to damp as it allows moisture to pass in and out of the paint itself. In contrast, many non-breathable paints are designed to prevent or restrict moisture from passing through the paint. While this might sound ideal, this also prevents moisture from escaping from within the wall, trapping it. This trapped moisture can cause damp and mould, plus peeling paint as the moisture tries to force its way out. However, there can be several reasons for walls becoming damp. Therefore, determining the cause of the damp is the best first step. Depending on the cause, using breathable building materials, like lime render or plaster with a breathable paint, can be a comprehensive solution for damp walls to consider.

Two of the well-known and popular brands of breathable paints we stock are Beeck Mineral Paints and Earthborn. Both offer a wide range of breathable paints in multiple colours. Other breathable and more traditional options include Cornerstone Lime Paint and Cornish Lime Limewash.

Black staining on a stone wall

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Need to clean stone masonry, render or brick? Find out more about cleaning methods to consider, things to avoid & tips to get successful results.


Several colours of mineral paint mixed together.

What Are Mineral Paints

Learn what distinguishes mineral paints from conventional alternatives and why they are a top choice for a breathable, sustainable, durable finish.


Outside view of Brims House

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88 thoughts on “Breathable Paints Explained”

  1. Dear Sir or Madam,

    I live in Norfolk and have an old barn near the coast (about 500 meters: I only mention this as salt mist may be relevant to the discussion). The barn is built with quite soft Norfolk brick and lime mortar. some are quite crumbly. I will be repairing the building over the next 3 years, replacing some brick, where they have determinate do away and reprinting with hydraulic lime mortar.

    my question is that much of the building will still want to absorbe a lot of water as the old bricks are so soft, so is there a solution I can use that’s ‘clear’ so as to create a bonded layer over the brick surface (and mortar) to protect them from further water and frost damage yet maintaining it to pass the maximum amount of water vapour. I do not want to trap moister in the building fabric.

    Your advice will be most welcome.


    • Dear Chris

      Apologies for my delay in reply, our website has recently undergone some changes and i now have access to the comments section.

      We do have a vapour permeable, protective coating that can be applied – Beeck SP Plus .

      However, as every application is unique i would recommend that you contact us on 01208 79779 and we can discuss your application and requirements in more detail.

      Kind Regards

      Adam Brown

  2. Hi,

    I was wondering if you could tell me how to prepare an exterior lime render house?

    I know you need to apply a lime wash first, but I want to know the best ways to apply the lime wash, the duration of times between coats and wether you need to apply a stabiliser before your 2 coats of breathable paint? … if you could give us a step by step guide on the correct method to use is appreciate it!

    Kind regards

    • Hi Paul

      Render applications can vary depending on the type of mortar, the finish you are looking to achieve, the host surface and also the location/exposure of the building.

      We do have some general guidelines on the website, however i would advise that you contact us on 01208 79779 and we can discuss the specific requirements for your application.

      Kind Regards

      Adam Brown

  3. Dear Adam, thank you for your very informative article on breathable paints. We have a house with lime plaster internally and a Dulux vinyl Matt undercoat has been put on. Dulux have said it is breathable with an SD of < 0.03. Should this be acceptable or is it impossible to have vinyl breathable paint with a low SD? We are considering trying to take it off. Thank you, Michelle.

    • Dear Michelle

      I would be quite surprised if a vinyl matt had such a low SD value, especially as low as 0.03. Have they provided any documentation to state this? Also it is worth checking that if the SD value is just for the undercoat or is it for the paint itself?

      An SD value of 0.03 would be suitable for a lime plaster

      If you have any questions please contact me on 01208 79779 or via email –

      • Thank you both so much for these posts. I have the same headache. Builder was told to use a breathable paint (and specifically not vinyl), but their decorator used a cheaper ‘normal’ matt emulsion as undercoat (i.e. not marketed as vinyl) followed by a topcoat of Dulux Trade Vinyl Matt. Dulux have told me that “The SD value for Dulux Trade Vinyl Matt is: V >680 S <0.03 V1 High" and that "<0.03 is the SD value- water-vapour diffusion equivalent air layer thickness
        V is the water-vapour tranmission rate so this is classified as V1 high".

        So is "water-vapour diffusion equivalent air layer thickness" definitely what an SD Value is meant to represent? If so, then Dulux are indeed claiming an SD value of <0.03 for Dulux trade Matt Vinyl.

        I should also point out that a different Dulux employee replied to an earlier email of mine (before I had learnt about SD values from your posts) to say that no Dulux paints are recommended for lime plaster! Although if the above SD value is correct, I do wonder whether they just can't be bothered with the extra liability of lime (perhaps due to the damp issues it is sometimes used to help).

        • Thank you for getting in touch.
          Firstly, I would seriously question the claim that the trade vinyl matt has an Sd Value of 0.03 as it is an acrylic co-polymer paint. If they are claiming this value I would ask for it in writing, I would also ask if this has been independently verified and which test method they are using.

          One of the reasons paint companies generally state that their paints cannot be used on lime is that they usually aren’t breathable enough and subsequently blister and fail.
          Many companies also state that their paints cannot be used on lime due to the alkalinity. If the lime has carbonated then it will no longer be alkaline. However, as these paints don’t typically have a low enough Sd value and don’t sufficiently allow for vapour/gas diffusion, this could slow the or prevent the lime from carbonating. If moisture then builds up behind the paint it could carry uncarbonated alkaline material with and this could also damage the paint, along with the moisture itself.

          Even if the Dulux is as good as they claim, you mention the painter has used a “cheaper normal matt emulsion” under it which may still not be breathable and which still seals the surface.
          In terms of ‘breathable paints’, the term breathable is completely meaningless when it comes to paint as there is no defined standard, so many paints (and other building materials) can claim to breathe, but they won’t breathe sufficiently for a lime plaster/render. If the paint brand wasn’t defined it can be very difficult as the paints used could have been selected with the best intention and under the understanding that this was the correct product to use.

          If you would like to discuss in further detail please don’t hesitate to give us a call.

    • Anne

      There is no defined way of telling the difference. However, there are a few tell tale signs that you could look for.

      Firstly masonry paint can look like a plastic coating and have a sheen. It is usually quite smooth and feels plastic when you rub against it.
      It can also be prone to cracking, these are usually very fine and will show up if you spray water over the wall. It is also prone to bubbling or peeling off the wall.

      A lime wash is usually quite dusty and can be brushed off the wall if rubbed forcefully enough.
      Lime wash will also change colour when it is wet, it usually goes darker and you can see it dry out.

      One way of telling the difference is to remove some of the paint from the surface. A masonry paint will likely come off in sheets due to its plastic content.

      If you would like to discuss this in more detail, please call us on 01208 79779.

  4. Breathable paint is the only type to use on old clay tile foundation blocks. The waterproof paints end up damaging the clay tile blocks.

  5. Hello, i have the ‘blistering’ and ‘bubbling’ problem on our 17th c house internal walls. Couple of questions:

    1) How do you prepare the wall to remove or paint over existing normal paint finish (eg. can i just lightly sand an paint over with earthborn for example?)

    2) How does earthborn compare to the other paints you mention? I dont know if the plaster is lime or not, is it suitable for covering either way?

    3) What advice do you have for bathrooms with very high humidity? To block the moisture going in with normal bathroom paints or to stay breathable and allow high humidity in?

    Thank you for any advice



    • Hi Craig

      Blistering and bubbling of the paint film is usually an indicator that there is moisture held within the substrate, this would suggest that the plaster has some level of permeability, so a breathable paint will likely help.

      To answer your questions –
      1) In terms of preparation there are several different methods. I would start by trying to peel and scrape back the failed areas and you may find that the paint removes with relative ease. From there sanding the surface may remove some of the more stubborn areas, however i would recommend that extra care is taken here as the sanding could damage the underlying plaster. If this these options do not address the issue you could look to use some form of paint stripper, we stock an environmentally friendly range of paint removal products – Scheidel. I would advise that the first two options are attempted to begin with, as they cost very little apart from your time. The majority of our internal paints can be applied over existing paint finishes, however a breathable paint is only as good as the surface it is applied too, so the problem could still persist.

      2) The Earthborn paints are very good paints, easy to use and suitable for both lime and modern plasters. All of our internal paints are relatively easy to use and they are all environmentally friendly alternatives to modern coatings. In terms of ‘Eco credentials’ the Aglaia range is probably the best, it is made exclusively from recycled and renewable crops, although both the Beeck and Earthborn are close. In terms of performance, longevity and vapour permeability we would advise the Beeck range, we have full performance data and have been supplying these for over 15 years. Every range we stock has paints that can be applied over numerous substrates, Earthborn and Aglaia will cover gypsum, lime and existing paint, within the Beeck range we would recommend using the Maxil Pro as this can cover different backgrounds, as well as offering the highest vapour permeability.

      3) In terms of high humidity areas this is not always straightforward. Firstly ventilation is key to deal with high humidity. Secondly the paint can help combat the issue of high humidity, but you will also need to rely on a suitable plaster. if the wall is vapour permeable (plaster, paint etc.) it will be capable of holding excess moisture when humidity rises and then release it again when the humidity lowers. Bathrooms are always problematic as the humidity is not constant and will always fluctuate. One common issue that can be found in bathrooms in all houses (new or old) is mould, the main cause is lack of ventilation, but the paint and plaster can also further the issue. If a surface is closed and unable to absorb and release moisture, it will allow condensation to form on the surface, if this is combined with a food source (usually dust) and then sufficient humidity, mould will form. If the wall is vapour permeable, this problem can be reduced. Also modern paints, especially bathroom paints, tend to contain higher chemical additions which can produce electrostatic charges, which in turn attracts dust, which is a food source for moulds. We wouldn’t recommend the use of Earthborn or Aglaia within a bathroom, but the Beeck range is perfectly suited to these constant moisture changes and can help address potential issues.

      If you would like to give us a call on 01208 79779 we can discuss your applications in more detail.

      • Thank you for your excellent reply above, looking at your Beeck page it states they are “only suited to a render that has not yet been painted”, as it’s an existing bathroom I’m guessing this is a problem?

        Also, do you recommend using Earthborn Wall Glaze before painting to stabilise sandy, powdery interior surface, again another sign of damp?

        Thank you


        • In regards to the “only suited to a render that has not yet been painted” – This relates to the Beeckosil system, which is one of the external paints they produce. The Maxol interior paint will work fine over existing painted surfaces. However, as i mentioned in my previous post it is all dependant on the existing make up of the wall as to how well any of these paints will perform.

          The wall glaze may help with crumbling plaster. Again it depends on the type of plaster – if you have gypsum plaster this is a sign of moisture breaking down the plaster and the glaze may not be able to stabilise the plaster. If the plaster is lime based, i would recommend using the Beeck Fixative, Fixative is the reactive component for the mineral paint systems and can be used to bind crumbling stone and lime plasters. We have used this successfully for several years.

          Any questions please contact me.

  6. We are in the process of exposing a sandstone wall in our living room. We’d like it to remain exposed but to paint it white. What would you advise -we don’t want to seal as it as we want the wall to breath. What advice would you give regarding the paint we should use? I read somewhere using limewash on sandstone where it’s not been used before can cause deterioration. Is it ok to paint without sealing the wall? Thanks.

    • Hi Ursula

      In regards to painting an exposed sandstone it has been stated that lime wash to an unpainted sand stone surface can cause deterioration. I would recommend the use of Beeck, Aglaia or Earthborn interior paint. These are all vapour permeable and will not seal the surface.

      For exposed mansonry we do favour the Beeck internal paint systems as they chemically bind to the surface, which offers excellent longevity and vapour permeability and can help stabilise the stone if it is crumbling.

      I would recommend that the surface is thoroughly cleaned down and any coatings removed, then 1 coat of Beeck Fixative (as a primer), followed by 1 or 2 coats of Beeck Maxol.

      If you wish to discuss this in more detail or have any questions, please contact us on 01208 79779.

  7. First, I must say its most helpful having all your ‘posts’ to read – as even though they are not my issues/situation they give one a greater understanding of different building problems (relating to build material/ paint surfaces/ past experiences/ best practice, etc), and the possible options & remedies open to each scenario.
    So, with this in mind that other may read my paint dilemma – could I seek your advice ? !

    My house is circa-1600 cob wall thatch house. It has for past 100yrs been owned and maintained by the MOD –and appears to have been ‘repaired’ & maintained to varying standards depending upon the materials available at the time, the money (cheapest) available to spend, and the vagaries of repair options & paint choice, depending upon the individual employed at the time (traditionalist or quick-win modernist) !

    I have just installed some new oak windows and so re-made the walls…which are in need of a re-paint (last done 20+yrs ago). So what paint to use ? !
    1. The base of all walls appears to be primarily flint (on no foundations) with lime mortar — presently painted with a black (bitumen type ?) painted skirt. When the wall dry’s out I can clearly see damp darker blotchy patches over many parts of the wall.
    2. In places the wall has sections of brick (no DPC) & lime type wet crumbly mortar (can be picked out easily with a finger-nail) –presumably not original and put in to strengthen & reinforce the cob-wall (which is 22inches thick).
    3. On the gable end (replaced window end) — half of the first floor wall is merely a wooden frame-work covered in lathe & plaster over-rendered in concrete (being just a 2 inches thick skin) – -the other half is cob. I presume the cob-wall previously went to the roof, but was removed to install this window when the house was ‘modernised’ in 1960s. The ground floor is totally brick over the cob.
    4. The other gable end wall is completely covered in 1-2inch thick concrete/pebble render – – which presumably encases the old cob-wall and strengthens it (though it could be brick behind it). Like the other end a window has been placed on the first floor – -and similarly the wall above it is just 2 inches thick.
    5. The front of the house is a mix of standard cob-wall, sections of brick, and areas of concrete render. When humidity conditions are high (on a hot day) a thick sticky ooze runs out of the wall down my windows (presumably some previous paint undercoat sealant system).
    6. All of the house back wall appears to be the original cob. . . but only 30% is exposed. The remaining 70% of the wall is internal: being attached to a single storey brick extension with no DPC & lower ground level internally. Therefore, it has its own problems with 40% of the paint & mortar missing, but this is understandable given its appalling design/construction . . .so any paint solution would never last !
    7. Internally, all walls have been re-lined with 2inch blocks & a plastic sheet …and interestingly I can see that the cavities are wall-papered ! Damp and condensation are a continuous battle …but restricted of course to the external walls.
    8. From my experience & your web-site advice sections …I would say all external walls are painted with modern masonry paint, as it appears to be a thick plastic-type layer that can be peeled off. If viewed on the side it appears very shiny (tiny reflective specks) and repels water well. Paint on the render zones is ‘as new’ and only in need of light touch-up. The paint on the bricks is falling off in vast patches being pushed out by the damp mortar. Most of the flint zones are similarly patched with 40% pushed out at the mortar joints. Leaving the cob-wall condition somewhere in between….generally sound with isolated minor lifting patches.

    So in short, all the damaged paintwork is at the mortar joints …in the brickwork and in the flint base. Given my wall is already painted (i.e. sealed) and would take many hours/weeks to strip off – – i can see little benefit of over-painting with your ‘breathable’ paint. And as the majority of lime mortar joints are so soft, damp & friable (and in places totally absent with gaps =mice ingress points) i am tempted to re-point the flint with ordinary hard mortar..inject some Dry-Zone…then cover with one of your breathable paints. My thoughts being; concentrate on the lower damp level /install hard mortar & flint chips to seal the ground-level area & prevent rodent attack / wire brush prep the entire black surface (likely i would break into existing paint surface) …. .then finish with your breathable /waterproof paint to help the moisture escape.
    But for the rest of the house— the ‘modern’ paint is generally sound/i cannot easily strip it off/ the walls look acceptable above 4 ft high…so make good the brick mortar joints (with ?), and just paint the rest of the house with standard (cheap) masonry paint !

    Apologies for the long description, but the more words i put down the more i realised i have been putting this task off for so long due to my quandary ! Can you help /advise ?

    • Hi Robert

      Firstly i apologise for the delayed response.

      It sounds like you have a number of potential issues that are causing damage and/or damp build up. Having read through your explanation, there are several ways to tackle these problems, however to truly address the issues you would likely be looking at extensive work. Which I think would be best discussed over the phone or face to face as there is not a one size fits all approach unfortunately.

      To answer your summary at the end, i would offer the following –

      Clearly the building has been touched up/repaired over the years with inappropriate materials that are causing problems. It doesn’t surprise me in any way that the majority of the damage is taking place at the mortar joints. These are often referred to as the evaporation zones, where the weaker mortar (compared to the brick) can enable the escape of moisture from within the fabric. Firstly i would not be recommend re-pointing in ‘hard cement’ mortar or using Dry Zone. This is just going to further trap moisture within the fabric, it will also seal the joints and further close down areas where moisture is trying to escape from. I would recommend re-pointing the joints with a lime based mortar, these areas (with appropriate paint) will then allow a point where moisture can escape and whilst it may not solve the overall issues, it will certainly offer the moisture a small route of escape. Strength and sealing are often seen as the answer, however a NHL based mortar (be it site mix or the Cornerstone ready mix range) will offer a reasonable strength and when combined with a mineral paint should prevent rodent attack. Whilst cement mortars are extremely hard, a solid wall building is likely to undergo thermal movement, as the cement is very dense it is unable to accommodate this movement leaving it brittle and prone to cracking. When cracking appears, water can be driven into the wall and unable to escape.

      I would recommend that a lime mortar is applied to any area where there is no mortar or where the mortar needs replacing. The areas where you are looking to apply a breathable paint, i would recommend removing any defect paint and cleaning the surface down with a fungicide/biocide and then apply the Beeck Renosil system.

      Given that this is not a straightforward application, if you would like to call us on 01208 79779 we discuss this in more detail.

  8. Hi,
    very interesting posts and helpful replies; any chance you could advise me on my plaster/paint problem?
    Ours is an old stone cottage, which we’ve repointed using lime mortar, and various other remedial work to put right previous ‘improvements’. The dining room was ‘renovated’ about 20 years ago, with a concrete floor, and gypsum plaster on the walls, which over the years has blown most of the way round the room in patches in the lowest 2-3 ft of the walls. We’ve remedied many of the long-term damp sources (added a french drain, lime pointing etc, even fixed the roof!), and would like to find a way to replaster the bottom part of the wall with something appropriate, but we don’t want to hack off and replaster the whole room if we can avoid it; we have a tight budget, and bigger problems to remedy, but we need to do something – it looks a real mess.
    What would you recommend in terms of approach, and materials… I’m not looking for forever perfection, but a cost effective solution to a mess that needs tidying up, without compounding the problem.
    Many thanks,

    • Dear Jo

      Whilst this issue is not uncommon there are several ways to address the problem, of which a few may be suitable. I have emailed you directly to discuss this in more detail and give an overview of what we believe could work.

      • Hi – I have just found your excellent website – I live in Malta – where by the older properties are all built with limestone. Some walls can be 3 foot thick and the ‘insulation’ for want of a better word is actually soil!
        I have stripped off all old plaster and completely re-plastered using lime – however; there are still moist discolouring on some of my walls ? – even lime paint is failing to ‘stick’ I can send you a photo if you like to show what I mean.
        should I seal this with anything?

        • Hi Julie

          From what you have mentioned it sounds like you have some form of contamination coming through the walls and plaster which is preventing the paint from adhering. This could be some form of soluble salts, which expand with available moisture and can force the paint coating from the plaster. Is the paint sticking/adhering in the areas where this stain is not coming through?

          In terms of sealing we would advise against this, as if it is salt contamination / efflorescence sealing the surface could move the salt to other areas within the wall or cause the salt expansion/growth within the wall, which can lead to larger issues in the future.

          Kind Regards

          Adam Brown.

      • Dear Adam, your site is one of the most useful on the entire internet! Thank you for the consideration you give to your replies. Jo’s query echoes our new circumstances, and it would be very helpful to see your reply if possible? We are also somewhat concerned that we might find medieval walls when we take the blown plaster off. May I ask if you think we should te-plaster a whole room or can we just do the wall with the affected plaster? Thank you.

        • Firstly what you are experiencing is a fairly common issue within renovated older properties. The ideal solution is to remove all of the gypsum plaster back to the underlying original fabric, this can then be followed with an appropriate lime render/plaster and an appropriate paint to allow vapour permeability to return to your wall.

          There are likely to compounding issues taking place within the wall. Firstly the coatings that are present are holding moisture captive, which as it builds up results in hydraulic pressure and breaks the coatings down. The second issue is the gypsum skim itself, as it is a salt, as moisture is held within the gypsum soluble salts can grow/expand and cause further deterioration.

          Ideally you would do the entire wall as this can then promote vapour permeability across a greater area. If can only tackle sections I would advise that the coatings are removed here and left exposed for as long as possible. This will help excessive moisture escape and if any salts are present hopefully they will form and can be brushed off. You can then clean down the surface with a dry brush and apply a lime based render/plaster. There are several options for the recoating, such as NHL or putty and these can be mixed on site or supplied as preblended products.

          I have two concerns –

          1. Cracking – where the two materials join/butt together there will be a difference in thermal expansion and you may find constant movement at the join, which can result in cracking. If some medium can be put in place to prevent the materials from touching this may address the problem. In terms of the join it is difficult to say what will work best, I have known in the past people chase out this section or leave it bare and apply some form of flexible mastic in its place.
          2. Moisture – the lime section will be vapour permeable and allow moisture to escape. However, there is always the risk that moisture will still be held in the higher gypsum sections so they may be prone to fail at a later date (similar to what is taking place in the lower sections). This problem may not manifest itself, but there is still the risk. The section issue may be excess moisture, as the moisture now has a point of escape through the lime you may find this area remains wet which can prevent the plaster from drying sufficiently for a while, in turn making decoration difficult or delayed. Or worst case scenario here is that if there is a high moisture content this will be pulled through the render/plaster and result in shrinkage cracking as the material sets, although If this happens and the cracking isn’t significant there are suitable fillers that can be used to rectify this. If the shrinkage cracking is excessive it can result in the mortar failing.

          In terms of doing multiple walls, this is ultimately your call but personally I would probably take the approach of ‘if it’s not broke, don’t fix it’. Great if you can remove and replaster everywhere but if the other walls are not showing signs of failure they could be left. Chances are that these walls may fail at some point, my advice would be to concentrate on the external walls first, as these will be subject to more water.

          Kind regards, Adam

  9. Hi, I’m in need of advice please. Ive recently moved. I’m trying to decorate a utility room wall that has been plastered (internal) with normal plaster. The modern plastic paint isn’t sticking too well in patches but I cant see obvious damp. The building is about 400 years old in places. I think this wall is part of the original building but it has been covered up and recently replastered I think to hide rising damp. The other side of the wall (very thick) is the old back lobby which has thicker plaster (maybe lime??) on it which has bubbled modern paint (I think its external house paint) on it. Here the bottom of the wall plaster is missing in small places, revealing old stone which at least lets that bit breathe. My question is, as I’m stuck with the modern plaster in the utility room, should I paint it with a lime based paint, does modern plaster breathe like old lime plaster? Will a lime based paint stick to it? Any advice welcome. Thanks, Kate.

    • Hi Kate

      Sorry for my late reply, i have been out of the office.

      There is no way to accurately state that a breathable paint will help the matter. The fact that the paint is failing is a sure sign that moisture is being held within the wall and is trying to escape. A breathable paint may allow this moisture to be released from the wall and help the issue. However, the main problem that you will have is the gypsum plaster itself, as this cannot deal with moisture in the same way as a lime plaster there is every chance that it will eventually fail at some point.

      In short a breathable paint may buy more time, but chances are that eventually the underlying plaster coating will fail. If the paint helps the moisture escape this should buy more time before a new plaster is needed. If you were to go down this route i wouldn’t recommend a lime based paint as these do not adhere very well to gypsum plasters. I would recommend using either Beeck Maxol (internal mineral paint) or Earthborn claypaint. It is worth noting that ideally the existing paint coating should be removed, as this has already failed and the paint is only as good as the surface it is applied too.

      If you have any questions please contact us on 01208 79779.

    • What a brilliant article, it has really helped me get my head around some issues we are having with the front outside wall of our home. Our house is an early 1990’s brick fronted terrace. I believe there is a spring of some sorts underneath where our row of houses are built and many of the neighbours have problems with damp, we are probably the least affected. The houses are on a small incline and the property at the bottom had the garden collapse into a huge hole a few years ago. The problem wall is coated internally with modern plaster and painted in latex emulsion. The brick outside has been treated with water repellant sealer in the past. There is a cellar under the room and the walls are dry down there. The problems appeared as efflorescence and bubbling paint, on further probing the paint peeled from the wall in big sheets like wallpaper and the plaster behind was visibly damp. I removed all the paint and allowed the wall to dry out before repainting it with latex paint. Over the last 3 or so years the bubbling has continued with some areas of staining appearing. We had a new window fitted in that wall a few years ago and this is when the problems seemed to start, but I suppose it could be coincidental. We have had the window refitted but unfortunately the problems persist. The window does not appear to be leaking and the brickwork and pointing are in good repair.
      I really need to address the issue with something more than the spot touch ups I’ve been doing but not sure of the best way to proceed. From reading your article I don’t think just removing the latex paint and repainting the wall with a breathable paint will be enough. Do you think removing the current plaster and replacing with lime plaster and then a breathable paint would work? Any advice very appreciated. Thank you.

      • Thank you for your message on our article. Would you please be able to give us some further information so we can put together an answer for you. What is the pointing? Where is the property – is it in an exposed area? Would you please be able to email some photos of the external and internal so we can see what you are referring to? Images can be sent to Many thanks.

  10. I am to paint a lime rendered solid wall, the last person who painted it left behind the left over paint, which is Leyland Super laytex High Opacity matt emulsion, can I paint over this paint with your Lime paint or will there be an issue with it, Thanks Gary

    • Hi Gary

      A lime based paint will not work over a latex based paint. A lime paint requires an absorbent background, which the current paint will not offer and the lime paint will likely wash off fairly easily.

      Are there any signs of the existing paint peeling/cracking? We do have paints that can be applied over your existing coating, such as the Beeck Renosil, although the paint is only as breathable as the surface it is applied too and unfortunately a latex paint will not offer a high level of breathability.

      If you would like to give me a call on 01208 79779 i can discuss this in more detail.

      Kind Regards

      Adam Brown

  11. Hi,

    I’m really sorry to bother you with this, but several bouts of Googling have failed to give me a clear answer, so finding a real human to pester has me hopeful. We live in a modern house (2013), of standard modern construction: breeze block, cement render (I presume) with standard exterior paint and internally plasterboard with modern plaster and modern interior paint. Outside of the house now needs repainting, as these things tend to do after 4 years. I really want to use an organic, natural paint, but since the house isn’t of traditional solid masonry construction I don’t know if I can or should. As in, would there a) be any point, since the walls aren’t built with breathability in a mind and b) be any actual problems down the line, if it was built with the expectation of using modern plastic paints inside and out? I know we would have to get the existing exterior emulsion removed before using a natural paint, but can such paints be used on modern cement render without causing problems, either to the structure or with the appearance of the paint down the line? Should I just go with modern, low-VOC paints as a compromise?

    Many thanks for your patience,

    Sarah Heaton (Dublin)

    • Hi Sarah

      It is perfectly fine to use these types of paint in both modern and historic construction.

      I have sent you an email which explains things in more detail and has the contact details for your local supplier.

      Kind Regards

      Adam Brown

  12. Dear Adam, I have found your website when I was searching the internet for internal natural plaster and paint for our cottage. We have a 17 months old daughter and I am not very keen on too many chemicals in paint. So I hope you can maybe give us some advice what to choose.
    We are currently renovating a 260 year old limestone cottage in Olney, Bucks. I would love to create a plain white cottage style look with preferably natural paints and plaster. Our workers have put in plasterboard. What would you advice we should get? Chalk paint? Limewash? Our decorator unfortunately has no experience working with this materials yet… Can we buy this materials from you?
    Our second headache are the exterior window lintels which have to be painted white. Van you advise us what kind of paint to choose so it’s weatherproof? I also have a video that shows everything I could send. Thank you in advance for taking the time to answer.
    Best regards,

    • Hi Barbara

      If you have plasterboard in place your best option is to likely finish this with gypsum plaster. You can use a natural lime based plaster, however it would not offer any real advantage other than being lower in embodied carbon. In terms of suitable paints i wouldn’t necessarily recommend a lime wash as its durability can be poor and is not designed for the backgrounds you have (modern plasters). A clay paint would work here, or Beeck Mineral Paint would also be suitable with the correct primer.

      In regards to the wood, we do have a couple of products that could work here, however it will depend on the condition of the wood and if any coatings are already in place.

      It will be far easier to discuss the specifics of your project over the phone and if you are able to give me a call on 01208 79779 i can run through the various options.

      Kind Regards
      Adam Brown

  13. Good Morning.

    What an excellent article.
    We have an old Tudor Farmhouse dating back to 1452. It was re-furnished for more modern living in 1975. We bought t in 1994.
    We are in the process of selling and the Buyers Surveyor has criticised the signs of a waterproof membrane within the external painted pebble-dash rendering. The membrane is pre-1975 when it was re-furnished. The Surveyor is concerned with the effect of no breath ability along the sole plate.
    The rendering has been there a long time and there are only two limited cracks at the bottom of the south-facing front wall. The rest, front and back, are unblemished. Hence, there are only two small areas of cracking , possibly due to the build-up of damp.
    The last coating was Sandtex applied around 10 years ago. It is now due re-painting and I would welcome advice on the treatment of the cracks and painting over the old Sandtex. I emphasise that virtually the whole wall front and back are in excellent condition with no signs of any bubbling.
    Can you recommend if any treatment is required before painting and can you recommend a paint.
    Many thanks

    • Hi Brian

      Thank you for your comments on the article.

      To be perfectly honest given that the membrane is in place and the walls have render and existing paint coatings a breathable paint will do very little to address the surveyors concerns. We do have paints that would be suitable for this type of application, such as Beeck Renosil, although the main benefits for your application would be improved longevity and a more environmentally friendly coating than compared to modern paints. The vapour permeability of the paint will be cancelled out as the paint is only as good as the surface it is applied to, which is likely to offer very limited to no moisture movement.

      If you were to go down the route of using Beeck Renosil the general application would be to fill any existing cracks, clean down the surfaces with a fungicide, apply a base coat of Beeck Renosil and a top coat of Beeck Renosil Fine.

      If you would like to discuss this in more detail please give me a call on 01208 79779.

      Kind Regards

      Adam Brown

  14. Thanks you for your helpful and prompt reply Adam. Very efficient service.

    Can I take comfort that at least since 1975, there has been no failure of the rendering except in 2 very localised areas low down where two hairline cracks no more than 600mm long, have occurred. As the two areas are small, it might be worth uncovering a sample area to see whats going on underneath.

    I’ll await the Surveyor’s Report and come back to you and accept your advice on paints.

    Thanks again and kind regards

  15. HI,
    We recently renovated a 17th Centry cottage and rendered our walls in lime plaster. WE want to use a breathable paint and we have youngish children. IS it possible to get samples of your paints to try out to test for texture/colour and durarability?
    MAny thanks

    • Thanks for your enquiry. Yes, it’s completely possible to get colour samples and we offer three different types of internal mineral paint which are all suitable and highly breathable. We’ll send the leaflets through by email and would recommend the Sensil which is a scrub resistant paint although all of them offer some resistance to being washed. Please let us know if you need any further assistance. Kind regards, Justine

  16. Hi, firstly thanks for the really informative article. I’m about to paint the front of my unpainted either rough cast or pebble dash 1900 house (I’m not sure which it is!)It has solid walls I I was wondering if breathable paint was the route to go. We have a bit of mould around the windows inside and I wouldn’t want to make this worse using Sandtex (which does say it is breathable) Also there are a few cracks in the the render so is it possible that it would be best just not to paint at all? Many thanks Ange

    • Hi Ange, I am glad you found the article informative.

      The difficulty with the term ‘breathable’ is that it doesn’t actually mean anything, most modern paints are ‘breathable’ to some extent, however the vast majority do not allow moisture to pass through them at a sufficient rate and this eventually leads to the moisture becoming trapped within the building.

      Do you know what your external finish comprises of? Cement or Lime? If the finish is cement based the rate of moisture transfer will be significantly reduced and as the paint is only as good as the surface it is applied to it may not solve the issue. However, if moisture is able to escape through the render, a suitable vapour permeable paint will ensure that it is not trapped. We would generally recommend the use of a mineral based paint due to its high vapour permeability and durability.

      Given that every application is unique if you would like to give us a call on 01208 79779 we can discuss suitable paints in more detail.

      Kind Regards


  17. I require a breathable
    Paint for interior.
    My zip is 97217 Oregon Portland.
    Cordwood hut. This has been recommended by
    The contractor as successful. Thanks

    • Hi Jackie

      Do you have any idea of the amount of paint you require? Or the size of the area you are looking to paint?

      We carry a wide range of breathable paints, are you looking for anything specific from the paint? i.e. durability, naturally sourced.

      Also what is the background that the paint is being applied too?

      Kind Regards

      Adam Brown

    • I have looked into the construction type further and unfortunately i don’t think we have any paints that would be suitable. Most of our paints are alkaline and wont work on top of wood and whilst we do have a range of lacquers designed for timber these are not suited for the cement that is present. There are some products we have that could potentially work but you would require at least 3 different primers and then a paint, this would work out as a very expensive procedure and due to the various primers involved the vapour permeability would be reduced.

      I have no experience with this construction type as its not something we see in the UK and from everything i have read it points to leaving the surface exposed and not applying a paint.

      I am sorry that we have been unable to help any further.

      Kind Regards


  18. Hi,
    Our house is over 100-years old, and is of brick construction with a cavity, it is lime rendered. Probably, for at least 40 years (?) the masonry has been painted with non-breathable acrylic paint. We have a large number of cracks resulting in damp in some areas within the house. The builders have ‘chased’ these cracks, and ‘repaired’ them with lime render, they have also changed 5 lintels and re-rendered in lime.

    We have been advised to use Beeck’s Renosil paint to paint the exterior of the house and the remaining hair-line cracks.

    Our highly experienced painter would like to use Sandtex fine textured matt, which is considerably cheaper that the Beecks.

    What would be the problems in terms of using the Sandtex, and the benefits we would accrue in terms of using the Beeck’s?
    We are happy to pay the difference if there are real and material benefits…
    One of our biggest, short term, issues is that we have just heard that we need to wait 4-6 weeks before we can paint over the new lime…….the builders had agreed to leave their scaffolding up for a few weeks after they had completed the work so that the painter could do the work.

    We would really value your advice on type of paint and timing……

    Best Wishes,

    • Hi Nerys

      Firstly can i ask where is the property?

      You mentioned that the construction has a cavity? Do you know if this has been added at a later date? The cavity wall was introduced in the early 1900’s and became common building practice from around the 1920’s. This cavity will likely benefit the wall as it will serve as a drain for any excessive moisture. With historic solid walled construction the building relies on the wall to accommodate moisture and allow it to be released. This is why we usually see modern type paints fail, as they do not readily allow moisture to escape, which causes build up in the wall.

      Has the existing paint showed any signs of failure?

      It is possible that this coating has caused moisture to be held captive in the wall and could be the reason why you are experiencing damp, although there may well be other factors that are contributing to this too. A common issue with modern paint is they offer limited flexibility, the wall itself will have a different thermal expansion to the paint on top, which can lead to cracking, once a crack appears water can then enter (driven by wind) but cannot escape at the same rate.

      The use of Renosil has several advantages over modern paints, although it really depends on the existing condition of the wall and the existing paint coating.

      It may be more beneficial if we can discuss this in more detail and if you are able to send any photos. If you are able to give me a call on 01208 79779 i can then talk through the Renosil and whether it is suitable for your application.

      Kind Regards

      Adam Brown.

  19. Hi. A great article. An odd question. I have an old granite property in Aberdeen. We have damp problems that show themselves inside.

    Despite major repointing and even re roofing the problem remains. Your thoughts on waterproofing granite with a clear paint ?


    • Good Morning

      This is a problem that we see on an almost daily basis, especially in Cornwall. With the re-pointing i am assuming that this has been done with a lime mortar?

      Also can i ask what is the build up of the internal walls? As this may have some impact on moisture movement and the ability for damp to present itself.

      We would strongly advise against using conventional waterproof coatings, as you don’t want to seal the building. Most of the products on the market claim to be ‘breathable’ but in fact offer such little moisture movement that they tend to cause long term damage.

      We do have a clear treatment, manufactured by Beeck, which is a water repellent. It is not a waterproof treatment, but will reject the vast majority of liquid that is subjected to the building. The product is called S P Plus and it works by being driven into the pore structure of the stone, it doesn’t close or seal the pores and will still allow for moisture movement, but it prevents water (liquid form) from entering. When rain hits an absorbent surface, the droplet spreads out and can be absorbed at a quicker rate, with the S P Plus the droplets are forced to bead and run off. The S P Plus will only work on a vertical surface as it requires the force of gravity to pull the bead down the wall, if the S P Plus is used on a horizontal surface it can still spread and be absorbed.

      The main reason that we advise the S P Plus is that it has actual tested and proven data for vapour permeability, with an Sd Value of 0.02, which makes it the equivalent of a mineral based paint. We also have case studies in the UK where the product has worked for over 10 years, even in severely exposed environments.

      If you have any questions or would like to discuss possible options in more detail, please give me a call.

      Kind Regards


  20. We have an old cottage (early 1800’s) that we have painstakingly refurbished over the last 12 years, with constant damp problems. We have relined interior walls with black jacking and false plaster board walls etc. Externally we have used Sandtex twice over the whole cottage (rendered walls). Should we try and take off the sandtex and repaint with a lime wash/lime paint?? If so, how? Internally should we sand back the walls to plaster and again use a lime wash/lime paint?

    • It is always difficult to comment or advise without seeing the property but are the damp issues still present? To be honest in terms of refurbishment, the approach you have undertaken wouldn’t be recommended by ourselves as applications such as blackjack and sandtex restrict and/or prevent moisture movement within the wall.
      Whilst removing the external paint and redecorating with a limewash or mineral paint would be better, this could be a large undertaking, if the paint coating is failing it will certainly be worth removing, or if its still in good condition you could potentially wait for a longer period until the paint begins to fail.
      Internally there would be little point in removing just the existing paint as limewash will not adhere to a gypsum based plaster and whist a mineral or clay paint will, the plasterboard and blackjack is going to prevent moisture movement, so whilst the paints are highly breathable, the wall build up is not. Again, it wouldn’t be detrimental to use these paints on the backgrounds you have, but they are only as good as the surface they are applied to.

  21. Hi, I bought an old house recently, it has some rooms that have been lined and painted. I dont know exactly what paint was used but presume modern ie non breathable paint. It seems in good condition – should I leave well alone or strip back to lime render and paint with breathable paint or just repaint as is to my taste and only strip back if problems arise in future?

    • Thank you for your enquiry. We would usually be of the opinion that if it’s not broken don’t fix it. It may well start to break down in the future and the addition of more modern paints may accelerate this by further restricting any breathability. However, stripping back and removing the existing coatings can be a large undertaking which is ultimately going to come down to your call. If you did decide to go back to the original lime render and plaster even on the internal external walls we have paints that will go over the existing coats as well as being breathable where they are able to be. Please read the following which may help you decide which way to proceed: and

      • Thank you! I think I will leave well alone so as with pandemic etc taking on extra work is a further challenge I dont need! How would I know if its breaking down under the wallpaper? Or will the lining paper start to peel off?

  22. Hello,
    We are doing up a terraced house built in 1870 with mainly lime plastered walls, in the top room one wall had been replastered with gypsum and due to water damage has subsequently blown. We have removed all the plaster from the wall and revealed the sandstone beneath. As it is an internal wall we are keen to leave it bare, we have tried to wash it to remove dust but wondered if there are any products which are clear and can be painted on to seal dust but not impact the walls breathability? Thank you!

  23. Hi,
    We’ve recently had a couple of walls re-plastered with lime. We’re looking to paint them and are trying to choose between lime wash and clay paint. It looks like clay paint is much longer lasting and more hard wearing than lime wash. How much longer is clay paint likely to last than lime wash? Do the benefits of clay paint outweigh the large additional cost of the paint?

    • Thanks for your enquiry. We usually find that when using limewash on fresh plaster you need around 5 coats and with some backgrounds you may need more than this. So whilst the limewash may start out as a cheaper alternative, it does need considerably more labour and more paint than the alternatives. Limewash also tends to be dusty, which may require more regularly redecorating when compared to other suitable paints. Externally you often find that limewash needs a refresh every few years as it weathers away. Internally this may not be as regular but you will likely find it doesn’t offer the same longevity as other paints.

      An alternative option to Limewash and the Earthborn Claypaint would be Beeck Maxil Pro, this offers a superior paint to the clay paint, with a higher opacity and scrub resistance at a slightly lower price than the Earthborn. Please let us know if you require further information.

  24. We have a 19th century stone built cottage close to the sea. We have stripped back the internal plaster on the outer walls and raked out the mortar 2″ -3″ and re-pointed with salt resisting mortar and render in preparation for dry walling and insulation. The external walls are now been stripped back to the stone with the mortar raked out 2″ – 2″ and repointed and rendered with a vapour permeable mix of sand, lime and cement in preparation of painting. I have been recommended a paint called Teknos Silkosan for the exterior masonry, but how does this compare with your Beeck mineral paint. Is this something that you can advise on?

    • Thank you for getting in touch. Whilst we cant advise on the use of other materials, looking at the technical information for Teknos Siloksan, it states it has an Sd Value of 5 which is extremely high and will offer virtually no moisture movement, we don’t advise the use of paints with an Sd Value higher than 0.08 as these are not truly breathable. We would certainly have a product in the Beeck range that will offer a high level of vapour permeability along with providing excellent durabiliy and a wide range of colours to choose from. Please let us know if we can be of further assistance.

  25. Hi, some advice please! I have recently used 4 coats of lime wash to our cellar walls, but am not happy with the finish as there are so many discoloured damp patches. Can I now apply a couple of layers of breathable paint over this for better aesthetics?

    • Thank you for getting in touch. It is very difficult to say without seeing it, but even with photos staining is almost impossible to state what it is. If the patches are just moisture the Beeck Maxil Pro should cover these, however if it’s a soluble stain this could still come through. Please let us know if we can be of further assistance.

  26. Hi
    Firstly let me say that as a novice where breathable paint/historic building materials are concerned, but have found this to be an excellent source of information. Thank you!
    I am in the process of purchasing a 17c cottage and am having a debate about the external paint – my surveyor has said it’s non-breathable hence the blisters and bubbles, but the owner is arguing that a breathable paint was used. I’ve asked for the details of said paint but in the meantime, is it correct to say that the blistering/bubbling and subsequent algae seen on the wall prove that it’s nom-breathable, or is that too simplistic? That’s what your article seems to suggest

    • Firstly thank you for your kind comment on our website regarding our Breathable Paints Explained article.

      The difficulty here is the term ‘breathable’, as we mention in the article it’s a meaningless term and unfortunately a lot of paints call themselves breathable. It is the level of vapour permeability we are concerned with and why we work with Sd Values and always recommend checking the Sd Value of any paint which claims to breathable. A lot of companies won’t reveal this information and whilst things are improving we still see paints with Sd Values of 5 claiming to be highly breathable.

      We would advise for any solid wall building and/or lime render that the paint should have as low an Sd Value as possible and should have an Sd Value between 0.01 and 0.05. The bubbling and peeling are signs that there is moisture being held behind the paint layer and the bubbling and peeling are usually signs of an increase in hydraulic pressure from this excess moisture forcing the paint layer from the wall. However, it is possible that the owner has applied a paint which stated it was breathable (to the best of their knowledge), but chances are this paint is not suitable for the wall in question.

      If we can be of further help please don’t hesitate to get in touch.

  27. Hello, May I agree with many others on your excellent and informative site. I have read the info on ‘breathability and SD factor’, not sure I completely understand it all! Our house is in the South Hams of Devon. We purchased in January 2019. It is a late 14th early 15th century listed building. So, no foundations, very thick walls and none of them vertical. The previous owner had it renovated sympathetically in 1980, it was listed when he had finished. Some damp in an interior ground floor wall where the paint is coming off in minute flakes, like dust. a little further on there are salts coming through the paint work. Only parts of this internal wall are affected. I don’t know what type of paint was applied. A specialist Plymouth company has quoted £3500 to £4000 to remove all plaster on the affected wall and replaster with materials which will allow the wall to breathe. it seems very expensive and lockdown has prevented that from starting! Have you any advice on solving the salts problem and the flaking ?

    • Thankyou for getting in touch. Without knowing what materials were used its very difficult to give specific advice, without trying to worry you in any way a sympathetic repair in the 1980s may be very different to what we would consider sympathetic today, again difficult to say without knowing the build-up.

      If the flaking is being caused by soluble salts within the wall, to be honest the only way to overcome this is to give it time, whilst this looks unsightly any intervention can force these salts back within the wall and they will simply return at a later date causing greater damage as they become more concentrated or they could work their way elsewhere causing further degradation.

      What you are seeing is referred to a efflorescence and this is where the salt is able to crystalise near or at the surface of the render, it is classed as an aesthetic issue as it only usually effects the very top surface of the render/plaster and in turn the paint. If the crystallising is restricted, cryptofloresence will be able to occur and this is where moisture movement becomes restricted and the salts crystalise within the render and or wall. Salt crystallisation has an expansive force of 2.1 tonne per m2 and if allowed to occur within the wall the damage can becomes structural and can result in render failure and or damage to the building fabric.

      Usually the best cure is to allow the wall time to release these salts and then try to find the route cause of the issue of how the salt has been able to escape, if the issue is recent has there been a leak? Is the building detailing sufficient, clean gutters etc etc. If you would like to send pictures of the internal and external we may be able to better advise. If you could send any images to we can take a look for you.

  28. We have bought a house where a single coat of dulux vinyl paint has been applied to lime plaster. Should we try and remove this with chemical stripper?
    Thank you!

    • Thank you for getting in touch. Asur or SG94 would work well, there are multiple other options too but we would recommend reading our guide to paint stripping which you can find here:
      With the Asur or SG94 most people buy a litre of each as a trial to see which product works best.
      Please let us know if we can help further.

  29. Hello. I’m about to embark on repair and repaint of our Regency townhouse (tall and thin) facade, it’s in Leamington Spa in the West Midlands. The main issues are peeling paint, moss growth and blown plaster, some of those may be caused by the previous paint layers of non-breathable masonry paint but it’s hard to tell. I’ll be using a lime render for the repairs and taking off the flaking paint as much as possible, but I’m looking for a paint system that will bond to the exisiting ‘masonry paint’ but also offer breathability for the new render. I’m thinking the Beek Renosil system that you supply, will that work and is it my best option? Thanks in advance. Andy

  30. I live in an old 1860 church and the sandstone windowsills have been painted and are growing mild and condensation is bad in winter (single glazed stained glass Windows) I think they have used generic masonry paint (I found massive tub in cupboard and all windows looked pristine white when I moved in. Will generic masonry paint be a factor in condensation and mould? Should they have used a breathable paint? Also I would like to take the paint off and leave the sandstone natural and unpainted and take the exist paint off, if I did that would it help condensation and mould? And would I have to use a special kind of paint to maintain and care for the “naked” sandstone

    • Hi Kelly, thanks for getting in touch. Generic masonry paint will restrict moisture movement through the substrate and can cause moisture to build up. Many generic paints contain plastics and these can result in an electrostatic charge which can attract dust, increased dust and moisture can contribute to mould.
      Masonry paints are also closed surfaces, designed to restrict water from passing through. As a closed surface they can contribute to condensation as moisture can condense on the painted surface.

      In terms of removing the paint, we have a range of non-harmful (to both the user and the stone) paint strippers which could safely remove the existing paint.
      In terms of maintenance/protection we don’t carry any specific products for this so we would be unable to comment/advise.

      If we can be of further assistance please let us know.

  31. We have a cottage with red Norfolk brick mortar and has been painted over the years with Weathershield which you can understand is just flaking off.

    Would you be so kind as to let me know before applying the correct paint what would the procedure be.

    Thank you very much for your help

    • Hi Gill, thanks for your enquiry. We would recommend removing as much of the Weathershield as you can as any paint will only be as good as the surface you’re applying it on to. If the paint underneath is flaking it could take off anything you put over the top. We have a system called Scheidel that will assist with this. There are two products, Asur and SG94 that will remove the paint. We recommend trialling a litre of each as one will work better than the other.
      Once you have as much of the Weathershield off as you can we have a paint called Renosil which will adhere to any sound paint that you can’t get off as well as bond to an unpainted surface. You can look at the details and the application guide here:
      Renosil can be coloured to over 240 shades so there’s plenty of colour choice.
      If you wanted to run through the system in greater detail please give us a call on 01208 79779 and we can talk you through it.

  32. Hi
    We have just bought. A 300 year old cob/thatch cottage. The walls appear to be painted with emulsion and also vinyl silk in some rooms and are bubbling in places. Especially round the bottom of the rooms downstairs. How do we fix this?. We understand that the walls have to breath and that we need to use a breathable paint.
    The bedroom has been papered. We have peeled some of it back and the render has come away down to the cob in some places . The cob appears to be dry and crumbly what do you advise us to do Do we just fill/skim the renderless holes with one of your lime fillers and then paint with one of your breathable paints? Any advise would be amazing. Thank you

    • Hi, thank you for getting in touch.
      It is likely that it is also the plaster/render which is contributing to this issue, so patching and redecorating may not solve the issue.
      If you would like to send images by email to we can take a look and come back to you.

  33. Hello there,
    I have recently had some part(internal) of my Victorian house (built in 1906) , with cavity wall, rendered with Lime mortar. This was previously rendered with cement, however, I removed the render due to damp issue and re-rendered with lime mortar. I understand that it is best to use breathable paints on the lime mortar.
    I am planning to repaint other parts of my house (internally) which has been rendered with cement mortar and painted with acrylic paint, by the previous owners.
    Is there any point in me using the breathable paints on top of the cement render, which is currently painted with acrylic paint? As it is a cement render it wouldn’t help with breathability, right?

  34. Hi, we live in Norfolk in a semi detached house which has some exterior flint walls, originally built in 1800. We have a problem in our living room whereby some of the interior plaster is bubbling and crumbly, presumably due to the moisture in the flint wall construction behind it. I have no idea of the type of plaster previously used on the interior and don’t know if the exterior has ever been weatherproofed in any way. We are hoping to decorate soon and were wondering if you could advise the best course of action in terms of fixing the plaster, the interior paint we might need to use to prevent it happening in the future, and whether we should do anything to the exterior. Thanks in advance.

    • Hi Tim, thanks for getting in touch with us. Without being able to see what you’re dealing with it’s really hard for us to comment. Could you please email some images of the both the interior and exterior highlighing any obvious issues to and we can take a look for you. We look forward to hearing back from you.

  35. Hi, I am looking to repaint an old interior stone and lime mortar wall. It used to be covered in a thick synthetic paint that kept all the moisture in. We’ve taken that off and let it dry for a few months and are now looking to repaint with Beeck Maxil Pro. But the wall has some very noticeable reddish brown stains (probably from damp) and I am worried that these will bleed through the new paint (I have filled some small holes and the red-brown colour has bled through the filler in places). Can you please let me know if there is any way of preventing this, e.g. are there stain blockers are compatible with this silicate paint? Thanks, Jess

  36. What an excellent website.
    We have recently refurbished a room in our old 1600s house using an insulating plaster (Dianthonite Thermactive + Argacem finishing plaster). I am now ready to paint with a breathable paint but am unsure how to begin. Do I need to apply a mist coat as with the usual plastered wall or do I need to put something on to make the wall paint adhere? Any advice would be wonderful. Thank you.

  37. Hi, I hope you might be able to help as we are pulling our hair out with confusion! We have a small 2 bed in Bristol and about a year ago a plasterer came in to redo the 2nd bedroom as there was some damp around the window – he knocked the wall back and rebuilt it using lime plaster and we left it to dry, then painted in breathable lime paint – however, a year later and the paint is still not dry – it is patchy and moist – some days it looks worse than others. Do you have any explanation for this? The outside render is not lime which is where the problem lies, but a builder has said it should ‘eventually’ dry out on the inside – we’ve had the roof redone to make sure there are no leaks coming in… we can’t get our head round what’s going on and why some days it’s worse / better!? We’d love to know what we can do to rectify this as it’s a real headache! Thank you

    • Thanks for getting in touch. If you’re able to email over some photos to we can take a look for you. Also if you’re able to let us know which paint product you used that would be helpful too. Many thanks, we look forward to hearing from you.


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