Stone cottage

[cottage_reno]

I have an old stone cottage on our block. Suspect the cottage to be 120 years old. Hasn't been lived in since the 60's but still has a solid roof and walls are solid. Looking at putting some life back into the building.

Any way, question is - the walls are lime plastered. They've been exposed to elements as there's no windows/ doors on the building. They were painted (not sure whether it's oil based paint or not). Would I be better have the walls re-plastered with lime plaster or erect a stud wall 50mm away from the walls and plasterboard? 

Do the walls need sanding down first to remove the layer of paint before lime plaster (over the small cracks and areas that are blown)? 

[MitchellMc]

Welcome to the Bunnings Workshop community @cottage_reno. It's wonderful to have you join us, and many thanks for your question about repairing walls.

For a historic stone cottage like yours, the choice really comes down to whether you want to preserve the character and “breathability” of the original walls or go for a more modern, easier-to-finish approach. Traditional lime plaster has a lot of benefits for old stone buildings: it’s flexible, breathable, and allows moisture to evaporate, which is really important with old masonry. Putting up a stud wall with plasterboard is certainly quicker and easier, but it essentially seals the wall off. That can trap moisture in the stone and lead to long-term issues like damp, mould, or stone deterioration, especially since your walls have been exposed for decades.

If you’re considering re-liming the walls, you will almost certainly need to remove any loose paint and flaky areas first. You don’t necessarily have to sand down everything, but any areas where paint is peeling or separating from the plaster need to be scraped back. Small cracks or “blown” areas can then be patched with lime plaster. However, you don’t want a layer of non-breathable paint underneath new lime plaster because it will compromise adhesion and trap moisture. If the lime-plastered walls have previously been painted with modern paint, it reduces their breathability to some extent. It could push the decision more toward covering the walls with studs and plasterboard.

Overall, for longevity and building health, I would lean towards repairing and re-plastering with lime plaster rather than putting up a stud wall. It’s more work, but it preserves the building and reduces the risk of future moisture problems.

Please let me know if you have any questions.

Mitchell