underpinning stone foundation
underpinning stone foundation
(OP)
I am working on a 150 year old building with perimeter stone rubble foundation walls supporting wall and roof load and first floor framing over a crawl space. The owner wants to add a full basement. I am worried about the stone rubble foundation falling apart during underpinning procedure. I am thinking about using a chemical grout to strengthen and stabilize the soil below the existing foundation. Then concrete underpinning can be installed in alternating 4' panels down to new basement level. Once completed, I would pour a cantilever retaining wall on the exterior face ("L" footing) to carry lateral soil loads. Any thoughts on this? Does this seem feasible?





RE: underpinning stone foundation
RE: underpinning stone foundation
RE: underpinning stone foundation
RE: underpinning stone foundation
Grouting would be specialist contractor work.
I would consider constructing the walls of the basement inside the line of the existing rubble walls as suggested by PSlem. Could use a secant pile approach to the walls using a low-headroom drill rig.
RE: underpinning stone foundation
Your bigger problem is that most experienced underpinning contractors are not interested in working on homes.
RE: underpinning stone foundation