How to protect sandstone?

[fshillit]

My home has sandstone window reveals. One of the reveals is quite badly disintegrating through weathering. I've brushed back the rotten sandstone, and although the surface is now uneven it doesn't look too bad andf I'd rather preserve it than replace or restore the reveal. Is their a tried and tested method or product I can apply to the sandstone surface to prevent it further disintegrating, or at least slow the weathering process down?

Thanks,

Francis

 

[Penners]

I'm not aware of any such product. There are probably "sealers" or "stabilisers" that will claim to help, but they're likely to bring their own problems by sealing moisture within the stone.

The problem you face is that the more the surface crumbles, the more it creates small recesses that act as pools to trap water. When this freezes, it exacerbates the spalling of the stone.

Sorry not to offer a solution - I hope others can.

 

[fshillit]

Yes, I would expect whatever could be applied would need to be 'breathable' to ensure no trapped moisture. Are there any traditional methods to this problem?

 

[Schoolmarm]

There are some people who advise lime watering to strengthen the outer layers. I have no idea if it works or not.

Search threw this thread up.

http://periodproperty.co.uk/forum/viewtopic.php?f=1&t=10106&p=117129&hilit=lime+watering#p117129

 

[MdB]

I think comments were made previously that lime watering can cause a crust which fails in one piece causing a more rapid degradation. (I know nothing about this - just what I remember)

Truro cathedral is being repaired at the moment due to dodgy sandstone. They are just replacing the damaged stuff. There has been no mention of any spray to slow down future degradation.

 

[stuart45]

Siloxane based sealers are said to allow masonry to breathe. They have been used in the USA for quite a few years.