Old foundation question??? - Posted by Chad

Posted by Mark on February 04, 2002 at 10:35:56:

The answer is… it depends! I am assuming you are talking about the outside surface of the foundation. If you have leaks then it would be best to seal it with a substance called “Thoroseal Plug”. If it is cosmetic, then you can mix up some Quickcrete masonry cement (sand plus cement) and smooth it into the joints, then tuckpoint it to match the rest of the foundation.

Old foundation question??? - Posted by Chad

Posted by Chad on February 04, 2002 at 09:30:21:

I have a duplex where the old rock/cement foundation is cracking and chipping away in some areas, and I would like to repair this. Does anyone have any suggestions on this type of repair? I am thinking I can just mix some quickcrete or something and smooth it over the cracks and holes and then paint it later. Any tips?

Chad in WI

Re: Old foundation question??? - Posted by Bryan in Cali

Posted by Bryan in Cali on February 04, 2002 at 22:18:16:

Here in Sacramento most of the old Victorians were built with BRICK foundations, which of course had become a worst nightmare for owners when downtown started to gentrify in the late 80s and people started snapping up homes that were boarded up in the 40s. Eventually the city passed a law saying that all rehabbed houses with brick foundations had to have the foundations replaced with modern concrete foundations. I don’t have knowledge of the type of foundation you’re talking about, but it may be natural (uncut) stone mixed in with the type of mortar used with bricks and poured. In that case, I would recommend hiring a professional to inspect it. You may have to jack up the house and replace the foundation.

Re: Old foundation question??? - Posted by GL(ON)

Posted by GL(ON) on February 04, 2002 at 11:21:21:

Around here there are plenty of pre 1900 houses with fieldstone foundations. They are made of big rocks with lime mortar in between. Every 100 years or so they need pointing, especially if it’s damp. Clean out the old mortar and put in new mortar, small rocks etc. Do a small section at a time. If you do this before the wall starts to bulge and crack, it will be good for another 100 years.You can get the mortar in sacks at the lumber yard.

If the foundation is actually falling down or bulging you are from 10 years to 50 years too late. You should consult a stonemason. You may need to shore up the house and rebuild a section of wall.

I have replaced short sections of damaged wall by digging out the old foundation and the outside soil with a backhoe, building a form and pouring a new section in concrete, throwing in all the old stones I could. This makes a permanent repair and you don’t need to be a mason.