Fieldstone foundations and masonry stone foundations, are the most common types below buildings build before 1915, seem to frequently be a concern for owners of old homes. With their sloping floors and cracked plaster, it’s only natural to suspect foundation failure to be the primary cause. A brief visual inspection will quickly disclose bulging, bowing, shifting or settlement that may require an experienced mason to repair. If there is a crumbly mortar coating, some minor gaps in the joints but the stones appear to be generally where the original builder placed them.
Moisture penetration through stone foundations not only erodes the mortar, but in excess, can cause pressure against the foundation and frost heaving in cold winter climates. The mortar coating applied on the interior is not going to stop water penetration and most stone foundations are going to allow moisture. Proper drainage around the perimeter of the building is important to avoid serious issues caused by water. The ground and impervious surfaces, like patios adjacent to the foundation, should have a positive slope away from the structure. Roof run-off should be collected in a wall maintained gutter system with downspouts discharging well away from the foundation walls. Sump pump discharge pipes should also be extended well away from the house.