Stopping Penetrating Damp

[davyb21]

I am looking for some advice on treating an old stone house for damp. The damp issue is penetrating damp as the stone is extremely porous. I have heard there are various products on the market now that are used to seal the stone from the outside (spraying or painting) but also allow the stone to breath. Does anyone know which are the best products to achieve this result and the ones to avoid?

Many Thanks

Davy

 

[Possel]

I would think very long and hard before doing anything permanent like that to the house. I really doubt that such products do work, and then what do you do?

Have the walls got cement pointing, or modern plaster inside? Make sure that you have sorted all the possible causes of dampness and let the house breathe for several months, before doing anything radical which you might regret.

 

[kitcorsa]

if you can inside the house take the walls back to brick, the tank the inside with tanking solution. I used FEBTANK in my house, you mix like plaster to think cream consistency then paint onto the walls. 2 coats are required minimum, and allow 24 hours between coats, and paint in right angles between coats (ie updown coat first then left right coat)

once dry then you can plaster over it with concrete based plaster.

If you using plaster boards, get the board which have polystyrene on the back as this will also stop dame damaging the decor.

on the out side you can paint the exterior with paint, if you want to keep the look of the brick you can use a clear silicone based paint... need to reapply ever 2 years or so. this will darken the brick a bit and give it a little shine. you could also have the house exterior professionally rendered.

 

[Possel]

And I would think even harder before tanking and using silicone paint. Google for a forum about "period property" and see what they have to say about how to treat an old house properly. They all have them and know what not to do!!

 

[stuart45]

And I would think even harder before tanking and using silicone paint. Google for a forum about "period property" and see what they have to say about how to treat an old house properly. They all have them and know what not to do!!

And every one will tell you not to tank the inside which traps moisture in the wall.
Siloxane sealer is said to allow the walls to breathe.
The inside should be lime plaster.

 

[davyb21]

Thanks for all the information guys.

The walls internally have already been tanked but it has been done pretty badly. We bought the property back in November and we are starting to find more issues as we go along. There is tanking is in downstairs but not fixed into the ground so the water just collects around the skirting board. A damp proof specialist has advised me that he can tape the existing tanking into a grove in the ground so that problem should be fixed.

To be honest I want to avoid pulling the plaster off the walls and doing it again if I can help it. It was the same specialist that said he could get hold of a product that would seal the outside of the building but still let the stone breath. He said it is pretty expensive hence the post on here as I am not 100% convinced either.

I would rather keep the outside looking like stone but don’t want to do anything that would be pointless or hard to undo. We live very high up on the pennines so the rain just relentlessly drives into the stone and after the summer we have had patches are appearing all over!

Do all of these silicone products have to be reapplied every 2 years? Has anyone ever used Siloxane sealer before? Am interested to see what experiences people have had with these types of sealers.

Thanks

Davy