Exposing external stone walls on a 200 year old cottage.

Torontoboy45

Currently, the walls are cement rendered, probably from the 1930’s, which of course has led to a few damp issues internally. I’ll be removing it in the summer. I’m not sure right now if the exterior was originally lime plastered but I’d like to keep the stone exposed with lime pointing. Other local properties built of the same material have bare exteriors. Could someone advise? Thanks.

MikeyBoy007

The stone would be quite vulnerable to water ingress even if a breathable sealer was applied.

 

If you intent on retaining the stone finish it would be important to point the stone jointwork with lime mortars that are struck flush so there is no opportunity for water to gather on ledges. A breathable masonry sealant such as Remmers Funcosil should then be applied- however, I would not recommend this option

Mike

L1011

That type of house was never meant to be bare stone, will probably be quite ugly as bare stone, and will never be quite right no matter what damp proofing you apply. I'm going somewhere between strongly suggesting and just outright pleading that you take the cement render off and lime render instead.

I've seen the results of various attempts to expose the stone on ~1830s cottages and they all end up looking shiny and ugly on the outside, and damp on the inside.

Furze99

https://www.boards.ie/discussion/2058225587/exposing-external-stone-walls-on-a-200-year-old-cottage

Are you sure the internal damp issues are due to the external rendering? Usually render was added for a reason, it wasn't just laid on for aesthetics.

Your internal damp could be cool walls (no insulation) and moisture within the cottage as a result condensing on them.

You can read a lot of talk about breathability of stone walls. At best rain that falls against a wall should evaporate back in dryer spells and in theory condensation on interior walls should dry out with adequate ventilation. But so much is to do with heating & ventilation internally. Look at how people used to live in older houses - one room heated, housecoats in winter, windows open often in daytime. Look at how people want to live now in old houses, wandering around in teeshirts.