Winter is fast approaching and we are starting to get calls from homeowners with stone foundations about cold air and mice in the basement. The typical issue there is that these stone foundations are pretty old, usually 80 to 100 years old. Mortar, kind of like the glue, is what holds these stones together. Well, if we were that old, we'd get a little decrepit and so does the mortar in between the stones. When that mortar ages it crumbles and you'll see a white powdery material on the floor; or if you drag your finger on the mortar it crumbles or has already crumbled. Once it crumbles it creates voids which allows in cold air. Think about all the stones in a stone foundation and the amount of mortar that can crumble. That's not like having a window open, it is probably more like having a sliding door wide open letting in cold air. But, it's not only letting cold air in, it can also let in furry friends like mice and rats, and even snakes.
To fix a stone foundation, we go in there and take out the mortar that has crumbled, is loose, or is non-existent. Then we put that mortar back in. This is called re-pointing a foundation. Right now in MA, RI and CT we are getting a lot of calls for this.