Sealing and Stabilising Composite Stone Sills.

[Jazzhands]

Hi, posted this in another thread but I think it was the wrong place so trying here.



My house has composite (I think that's what it's called e.g. they are cast rather than solid stone) stone lintels and sills on all the windows. The ones at the front get a battering from the weather and have corroded in places but moreover the surfaces are powdery and crumbling.
I am looking for a product that can be applied to the lintels/sills that will seal and stabilise the surface to help prevent further wear without discolouring the stone or making the surface glossy.

Can anyone recommend anything?

 

[^woody^]

I would suspect that you really need to know the cause of the erosion - apart from the weather that is. Design, mix or quality of manufacture can all cause this problem and may not be solved by such a magic coating.

A silane based water repellent may help deal with excess water and the subsequent frost damage, but if the actual mix is weak and pores too large, then it may need a new surface dressing to protect it.

 

[catlad]

I've seen this before and on not very old houses.
Its cheap and doesn't last! Good look