Repairs for fieldstone foundation

[max d]

The old part of house was built in 1860, fieldstone foundation & crawl space. Large gaps between the stones and field mice go in-out.
The newer addition has a full basement, poured concrete foundation on 3 sides. The party wall is composed of fieldstones from the cellar floor up to the dirt floor of the crawl space; The crawl space is then open to the full basement area with no wall.

Rain water tends to collect near the fieldstone foundation. One day after rain collects in this area, water is in the full cellar. I believe it takes about 1 day for the water to go through the fieldstone foundation and seep through the clay soil to the full cellar.

Next week, an excavator is opening up the entire length of this fieldstone wall for a new water service, an opportunity to repair fieldstone wall.

I've thought of using mortor on the openings in the fieldstone, as well as placing a sheet of rubber roofing vertically along the side before it is backfilled.

I would appreciate any comment that you may have.

[Admin]

First the old timers when setting the stone foundation made it nice on the inside where you would see it, and the stones on the outside go every which way.

To remove all the soil away from a stone foundation is a tricky project. Make sure your excavator is careful. Repointing the stone foundation is fine. If the stones are not too irregular you may be able to wire brush the walls and joints and then apply a rubberized membrane like Tremproof 60.

Hope this helps. SteveA