I’m needing to remove concrete render from Welsh stone walls, and repoint using lime. The guides are very helpful. I do however have a couple of questions –
1. how much lime mortar can you mix at a time? Will it go off in the bucket, or given the slow drying time, is this something you don’t need to worry about?
2. When chiselling out the concrete and repointing, should this be done all at once, or in stages i.e chisel out an area of concrete, repoint, hang hessian and then chisel out the next area?
3. If you can chisel out the entire wall in one go, does you have to do the repointing all in one go? If not, what do you do with the wall during sessions? Just hang hessian over the bit you’ve done? Is there a particular technique you need to employ to join the pointing you did the day before to the newer pointing?
Many thanks in advance for your advice!
Thanks for contacting us.
In answer to your questions:
- This will be dependent on the lime being used, but you will have several hours (anywhere from 8 to 24), with NHLs and with lime putty, if you keep the mortar sealed it will last pretty much indefinitely.
2. We would generally recommend removing all of the mortar first if possible.
3. The pointing can be done in sections, in most cases the pointing will be a relatively slow process and done in sections, as long as each fresh section is protected and kept damp for at least a week it should be fine.
Here is a link to our Pointing Guide: https://cornishlime.co.uk/application-guides/lime-mortars-for-pointing/
Please let us know if we can be of further help.
