Hello,
I have a house from 1929 with an uninsulated basement floor. I'm now considering converting parts of it into a bathroom and a hallway, about 15 m2. So, I'm thinking of breaking out/digging out/insulating and pouring a new floor. It's a 1.5-story villa with a basement (split-level house).
I wanted to check with you if you could help enlighten me about the dangers of digging out the basement.
There's an exterior wall that needs to be "freed," which has soil pressure about 1.5 meters up the wall. It is 3.2 meters of a wall that is 4.2 meters long. Internal measurements.
The house stands on sandy soil (which feels very good for the digging).
It's built with exterior walls that are about 45cm (sometimes a bit thicker) of poured concrete.
But my question is: No one ever talks about it being a problem to dig down to the bottom edge of the wall. So, should we not be so worried about the soil pressure? But I've been told it's a big no-no to go under the wall.
What are the risks involved with that? I understand that the soil right next to the wall becomes loosened, and the wall loses some of its bearing capacity a bit under the wall during construction? Anything else that's dangerous? Long-term?
So it's the risks I'm after? And not if one were to get the idea to dig down 1 meter, but rather 0-20cm.
