When repairs go wrong
Masons get called out to look at numerous problems, many of which have been patched (or botched) up by previous tradesmen. I’ve seen ‘repairs’ using sand and cement, concrete, neat cement, plaster of paris, levelling compound, decorators’ caulk and others. None will look the same as your lovely stonework, in the same way that concrete and cement don’t look the same as Portland stone.
Why repairs in other materials crack
The reason things crack is they expand and contract at different rates in the heat and cold. Over the seasons this will gradually prize them apart. Here’s a good example of an awful repair using concrete on a church porch. Not only is it hideous, but it’s already failed. It’s a totally different colour and material to both the York slab and the Bath stone jambs.
A poor repair to stone, using concrete.
So what do you use?
If you don’t have stone to piece-in there are a variety of products available via mail-order from specialists. If your property is listed you should be consulting Historic England, Cadw or Historic Scotland or your own regional/national version. There is a whole raft of chemistry analysis of various products so it will be easier to ask direct. Or you can drop me a line.
If you are based in Surrey or South West London I’d love to help. For a free quote to give your building the love it deserves, please call Geraint on 07803908066.