Sandstone sill repair

[Sainted White House]

Our Edwardian house has some seriously cracked window sills! I suspect they are causing the damp in the front room as the cracks go under the window.

Right now, replacing them is not an option. We don't have the funds. I'm a competent diy'er though. I just need help knowing what to use!

How can I fill these cracks and stop water coming in?

 

[Sainted White House]

Added. The house is covered in tyrolean. I think these cracks are pretty old because there was cement in them. I clean that and the debris out.

 

[Toby Newell]

Our Edwardian house has some seriously cracked window sills! I suspect they are causing the damp in the front room as the cracks go under the window.

Right now, replacing them is not an option. We don't have the funds. I'm a competent diy'er though. I just need help knowing what to use!

How can I fill these cracks and stop water coming in?

View attachment 11575

View attachment 11576

Contact 3C sealants and ask them, they will have a product and be able to advise.

Possibly the stuff I am ordering from them next week, a cementatious epoxy filler.

But also wait for other opinions. In general all materials expand and contract so in the battle between hard and soft, hard wins, soft loses.

And thus using a hard mix filler ie high cement or an epoxy may be structurally sound and waterproof at the start but after a few heat / freeze cycles may spall the softer sandstone. The epoxy is the cheapest on the market from their website but is still £114 for 10kg.

A soft lime mix as long as it holds won't be 100% waterproof but somewhat breathable and should be soft enough not to spall the stone.

 

[mardinor]

Are you intending to paint them after filling or leave bare?

 

[Sainted White House]

Are you intending to paint them after filling or leave bare?

Planning on painting them.