How to Repair an Old Stone Foundation

Old stone foundations are a beautiful part of American House building heritage. They have been around for years but are now an esthetic look instead an actual structural load bearing foundation. If your home is over 50 years or older and you have a stone foundation wall it probably is in need of repair. Many times the structure under the home is damaged from water and a professional is required to evaluate the extent of this damage. Snow, ice, and water cause serious problems if left untouched. If you see any loose stones, sagging floors or crumbling stones, it’s in need of some work.

If you plan on attempting this repair on your own, you should look in the basement or the crawl space, at the floor joists. If you see any structural damage to the surrounding wood, then it needs to be replaced. If not and the surrounding wood looks good then you can fix a crumbling foundation on your own.

Start by assessing the damage under the home. After finding the area that needs to be repaired, fix the wood by replacing it or scabbing on the side with an equal or better grade of lumber. The floor is probably sagging in the area and needs to be lifted upwards before attaching a scab or replacing the rotted wood. Use a large piece of wood twice he length of the sag. Place posts under the joists to support the wood beam. Using a floor jack at least 1 �½ tons, place under the temporary beam. Put a piece of wood or block under the floor jack to prevent it from sinking into the ground underneath of a crawl space. Use the jack to lift the temporary beam up. Slowly raise the jack one click at a time. Once the floor is raised to its original height, replace any rotten beams with scabs and replace any loose sill plates.

Once the floor is repaired, the foundation is next. Pull out any loose stones. Replace any stones that are damaged or broken. Mix mortar to secure the stones and replace. If the wall looks like it can’t hold the weight, it probably won’t. You will need to create a block foundation behind the existing foundation wall. Dig a small trench behind the old block wall about 8×16. Fill with ready mix concrete and let dry for 48 hours or longer until it cures. Use concrete block to stack underneath of each beam to help support the weight of the beams.