Fixing crumbling masonry
October 10, 2010 12:12 PM Subscribe
What kind of mortar should I use for this fugly masonry?
My house is old, with a foundation and chimney made from fieldstone and some kind of mortar-ish substance. It was built in the mid-forties, in the style that for some reason was popular around here— of stone with lots of thick mortar between, and bead joints. I think it's kind of ugly, but I need to try and match it, at least a little. There are many areas where the mortar is crumbling, especially the front steps, which I'm undertaking as the starting fix. The "mortar", as it is, seems really sandy. I bought some S-type mortar and worked on a little corner, but it looks very dark grey and not very sandy, and I don't want it to look too different. I was thinking of using just a premixed sand mix concrete, but will that work for thick joints between stone? Should I add anything? Use something else entirely? I've been hard-pressed to find information on this type of masonry online.
My house is old, with a foundation and chimney made from fieldstone and some kind of mortar-ish substance. It was built in the mid-forties, in the style that for some reason was popular around here— of stone with lots of thick mortar between, and bead joints. I think it's kind of ugly, but I need to try and match it, at least a little. There are many areas where the mortar is crumbling, especially the front steps, which I'm undertaking as the starting fix. The "mortar", as it is, seems really sandy. I bought some S-type mortar and worked on a little corner, but it looks very dark grey and not very sandy, and I don't want it to look too different. I was thinking of using just a premixed sand mix concrete, but will that work for thick joints between stone? Should I add anything? Use something else entirely? I've been hard-pressed to find information on this type of masonry online.
Could it be lime mortar? A lot of older buildings use this, and nearly everything pre-20th C does. It tends to be lighter and softer than cement based mortar. If it is, you should be able to buy some from a specialist builders' merchant.
posted by rhymer at 2:20 PM on October 10, 2010
posted by rhymer at 2:20 PM on October 10, 2010
I think it has to be lime mortar.
Its a mix of sand water and lime, don't remember the ratios but it was and is still very common and dependable.
posted by Max Power at 2:32 PM on October 10, 2010
Its a mix of sand water and lime, don't remember the ratios but it was and is still very common and dependable.
posted by Max Power at 2:32 PM on October 10, 2010
3rding the lime mortar notion. Repointing masonry to match existing is always a tough prospect, even for professionals, so give yourself some patience and time to make a match.
posted by meinvt at 3:36 PM on October 10, 2010
posted by meinvt at 3:36 PM on October 10, 2010
This thread is closed to new comments.
posted by Bruce H. at 2:16 PM on October 10, 2010