Usually limestone, sandstone, or fieldstone, a well built and maintained stone foundation can last centuries. While the stones may be bonded or repaired with mortar, they stay in place without it.
Most weren’t built watertight. Frost, roots, and poor drainage can cause shifting. The stones can settle, causing movement and creating gaps for pests.
Every spring
Step 1: Begin inside your home. Check for cracks in the walls, slanted floors, or windows and doors that don’t open properly. These issues could be signs of a shifting foundation.
Step 2: If your foundation stones are always wet, even when it’s dry outside, or if you notice moss, mold, white staining (efflorescence), or standing water in your basement, you may have a drainage problem. Contact a professional.
Step 3: Check your foundation wall for loose stones, buckling, and bulging. If you find any of these issues, have a professional take a look.
Step 4: Remove anything growing on your foundation. Moss, lichen, mold, and vines can damage mortar.
Step 5: Not all stone foundations need mortar. If your foundation does have mortar between the stones, check for crumbling, flaking, or missing patches. The mortar may have been applied to solve a previous problem and should be repaired.