Limewash Application Guide: How to Successfully Apply Limewash

If you’re looking to refresh your home’s exterior with a breathable and traditional paint finish, limewash application is a great idea. Limewash, a mixture of slaked lime, natural pigments, and water, has been used for centuries to create a beautiful and durable finish on various surfaces, including brick, lime plaster, and lime render.

In this guide, we’ll take you through the limewash application process, offering step-by-step instructions for applying limewash correctly.

What Applications Can Lime Be Used For?

Lime is an extremely versatile building material, that has been used (in some form or other) on any building built before the 20th Century. Despite the advances within the paint industry and the vast array of paints available to today’s consumers, there are still many occasions where limewash is the most appropriate and economic form of decoration for older buildings.

When we mention older buildings, we refer to those of solid wall construction, without a cavity and often no damp-proof course. This type of construction will always contain varying degrees of moisture and rely on the building fabric, including paints, to allow moisture to migrate freely and escape. Materials such as cement based mortars and renders, along with modern masonry and emulsion paints, serve to hold moisture captive within this type of building. If the moisture is allowed to accumulate, this can result in deterioration and failure within the building fabric as “moisture is the engine of decay”.

What is Limewash?

Buchner Limewash

Research carried out at all levels has proven limewash to be one of (if not) the most permeable type of decorative finish available. Combine this with the fact that it has been used as a decorative finish for thousands of years throughout the world, there is no doubt that it is a tried and tested decorative medium. Interested in other breathable options? Read more about breathable paints.

Limewash, in its simplest form, is calcium hydroxide (slaked lime) suspended in water. After application, the water evaporates and atmospheric carbon dioxide combines with the wash to form calcium carbonate, this process is known as carbonation. During the carbonation process the limewash hardens, develops its colour and bonds to the substrate.

A successful application of limewash should form a thin sheet of limestone on the surface. Carbonation can be an extremely slow process and it is essential not to allow the limewash to dry too quickly. An application process of one coat per day must be followed.

It is also important that weather conditions are suitable. Limewash should not be applied in strong drying winds or under strong direct sunlight and certainly not if rain threatens. If works have to be carried out or continued under unfavourable conditions, adequate measures should be taken to protect the works. For example, under strong direct sunlight, the coat of wash should be misted with a sprayer.

Limewash Preparation

As limewash absorbs into the surface, it works best when applied to more porous substrates, such as lime plaster, clay brick, soft stone etc. While it may appear to adhere to impervious surfaces It’s unlikely that it will provide as durable a coating as the lack of suction will impair its overall effectiveness. Its use on timber, although practiced in the past, should be questioned today by the novice, not that we are advising against its use.

To ensure that the lime wash soaks into surfaces effectively, surfaces should be clean and free from grease and vegetable matter, such as lichens etc. All loose and/or flaking material should be removed. Any organic growth should be treated in an appropriate manner, such as using D/2 Biological Solution (in accordance with manufacturer’s instructions), and all treated material prepared/removed prior to the application of limewash.

Find out more about D/2 Biological Solution

Limewash Application: What You Need to Know

It is important that a rule of one coat per day is followed, this allows each coat time to carbonate. Recoating too soon may result in the previous coat pulling away from the surface and can prevent sufficient carbonation.

Apply limewash using a large, long hair brush. Application should be vigorous, working the wash into the substrate, using horizontal, vertical and diagonal strokes.

Limewash has to be applied as a thin coat and evenly across the surface. Working in areas of 1m2 work the limewash into the surface with a scouring action with the brush in a circular motion. Limewash should always be applied in a manner where a wet edge is maintained, this will help avoid scarring and lines from excess build-up of material.

If limewash is applied too thick or heavy, this can result in crazing and cracking, should this occur and the results unacceptable, wash the surface with hot water and a stiff bristle brush (i.e. a churn brush).

Ready mixed limewash is supplied in plastic containers; upon opening the container mix the limewash thoroughly using appropriate tools. Mixers that can be attached to an electric drill are very useful , however a simple stick can also be effective. Browse our range of limewash.

Browse our range of breathable paints

Stir vigorously until the contents are one, this needs to be repeated every ten to fifteen minutes during application. As limewash is suspended in water, the lime will fall out of suspension to the bottom of the tub, so constant and continued stirring is important.  The last brushful should be as thin as the first. Splashes should not be left too long before wiping up.

Limewash Application Steps

Step 1: Prepare the Surface

Make sure the surface is clean and free of debris. It is important to check that any previous coatings are absorbent and compatible with the new limewash.. If the surface has been previously limewashed, remove any loose or flaking limewash.

Step 2: Mix the Limewash

In a bucket, mix the lime putty with water to create a milky/creamy consistency. If you’re using natural pigments, add them now and stir well. 

Step 3: Apply the First Coat

Use your brush to apply the first coat of limewash evenly on the surface. Work from the top down, maintaining a wet edge to prevent lap marks on the next coat.

Step 4: Subsequent Thin Coats

After the first coat dries, typically within 24 hours, apply the second coat and subsequent coats in the same manner. Remember the limewash needs to be applied thinly for a semi-transparent finish. Depending on your project, you may need to apply several coats to achieve the desired effect.

Step 5: Re-Coat as Needed

If you want to enhance the coverage or colour, you can recoat with additional limewash. Always maintain a wet edge between coats for a consistent finish.

Keeping Health & Safety in Mind

It’s important to keep in mind your health and safety COSHH Assessment when using limewash. Limewash is alkaline so every effort must be made to prevent any from getting into one’s eyes, however, in the event of this happening, rinse the eye(s) thoroughly for several minutes.

Limewash is alkaline so every effort must be made to prevent any from getting into ones eyes, in the event of this happening rinse the eye(s) thoroughly for several minutes, should discomfort continue seek medical attention straight away.  It is advisable to keep a bottle of proprietary eyewash to hand for irrigation purposes.

The wearing of gloves along with other Personnel Protective Equipment is advised as limewash is alkaline and it can dry the skin along with more serious Dermatological affects. Looking to get started?

Browse our range of PPE.

There are no risks from fumes, vapours or burning when heated.  By virtue of the way it should be applied lime washing can be a messy operation and the wearing of overalls or similar along with adequate protection of fittings is advised.

Top Tips For a Successful Limewash Application

Ideal for porous surfaces to create a breathable finish

Limewash is ideal for porous surfaces like brick, lime plaster, and lime render, as it absorbs into the surface and creates a breathable finish.

Plan for the weather

Pay attention to weather conditions, as limewash should be applied in dry weather to ensure proper adhesion.

A great alternative for interior spaces

For internal use, limewash can be a great alternative to traditional paint, providing a breathable and budget-friendly finish.


Summing it up

Limewash is a simple yet effective way to create a beautiful, breathable finish for your exterior walls or previously limewashed surfaces. By following these steps and using the right tools, you can achieve a stunning and traditional paint finish that stands the test of time. Remember to apply several thin coats to get the best results, and don’t forget your protective gloves and eye protection during the application process.

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.

2 thoughts on “Limewash Application Guide: How to Successfully Apply Limewash”

  1. I have newly lime plastered walls, some with a wattle and daub base. I’m waiting for the plaster to dry out but I don’t know what is an acceptable moisture reading on my damp meter. Can you please help?

    Regards

    Derek Schroder

    Reply
  2. We now have an internal stone wall which has had a 3 coat lime render applied – how long would you recommend to wait between the final finishing pass and applying limewash?

    Reply

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