How to Repair a Stone Foundation
- 1). Chip away the area around the crack with a hammer and chisel, going a half-inch or a little bit deeper.
- 2). Clean all the dust and debris from the crack with a stiff brush or shop-vac.
- 3). Mix a fresh batch of mortar, following the instructions on the bag, until it has the consistency of peanut butter.
- 4). Pack the mortar tightly into the crack with a putty knife.
- 5). Let the mortar set until it is solid, but still soft enough that it's malleable (check the label on the bag to see the drying time).
- 6). Pack the mortar in deeper and smooth the surface, using a jointer, a tongue depressor or a flat piece of plastic.
- 7). Scrape off any excess mortar that gets onto the stones around the crack with a trowel.
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