Expert: Stephen Major (Owner--Major Design Group) - 4/30/2007

Question
Hi,
One wall of our house sits on top of a deteriorated slab (the slab is a barn
floor). The barn is being taken down and the slab...save for about a foot or so
away from the house wall, will be taken out as well. The top plate for the wall  
that sits on the slab is nailed to an 8 x 8 beam (house is circa 1850
timberframe). Once I've got the slab out, I plan to dig out in maybe 3 areas
under the wall-including the remaining foot or so of the slab, remove those
slab chunks, and fill the voids with rebarred concrete. Does this sound like a
doable plan? Also, since the top plate for this wall is nailed to this big
beam,should I need anything more than a couple of 6 ton hydrolic jacks
sitting on blocks to hold up the wall as I dig it out and pour?
Thanks in advance!

Answer
Michael,

I pulled your question from the Question Pool.  Your plan sounds good, and it sounds like the wall probably isn't load-bearing considering the large beam.  But you should try to add temporary support anyhow, in case there are loads that you don't realize, or if the beam itself is compromised in some way.

I'm not sure what you mean by digging out in 3 areas, but if you do install a new concrete foundation beneath the wall, it must extend to below your local frost penetration depth and have vertical sides, or you could risk the possibility of it heaving during the winter.  Good subsurface drainage helps prevent this situation also.

Let me know if you have additional questions.

--Steve Major