Stone foundation and wood shims under floor joists
 

Hi all,

I bought a 150 year old century home a couple of months ago, the house has a
stone foundation with notched floor joists resting on the foundation. Along
one wall most of the joists have been shimmed with wood towards the inside
of the foundation, towards the rear the joist appears to still be supported
by the foundation. I'm a bit concerned that these wood shims will get
crushed over time and was wondering what sort of longer term solutions would
be used for this. The home inspector suggested poring some new footings and
adding new posts to properly support the joists. He suggested doing this in
conjunction with putting in a more permanent solution to a few jacks that
have been used in the basement. Note the floor is cement but I'm guessing
it's a pretty thin layer since the existing jacks (in other parts of the
house) have been placed on wood planks to spread the load.

Any suggestions or resources to look at with regards to this? I haven't been
able to locate too much info about it myself and I'd prefer to educate
myself a bit before bringing in contractors to offer opinions and bid on
possible work.

Thanks,

Gerald

What you seem to think as "temporary" might actually be fine, more or
less permanently. Maybe not -- can't tell from here.

Wood shims are not a big deal. They won't "crush" any time soon. If,
eventually, after decades they do crush (or, more likely, get wet and
rot, or something), the fix is to just hammer a new shim in.

Of course, if it is a matter of the walls not being able to support the
load, then yes, you need to look in to new footings or something.

The temporary floor jacks are also permanent. They should last a few
decades, and if you don't have a moisture problem, many decades. The
"right" way to do it is cut a hole in the concrete (4" thick is
typical, thinner is common but not great), dig down a bit, and put in a
decent sized block of concrete on which to set the jack. On the other
hand, just spreading the load works pretty well in practice, just using
a think wood block, or a poured concrete block on top of the floor.

If it were me: I'd check the walls and floor for cracks, crumbling, and
settling, especially near the joist slots and jack posts. If everything
seems to be sound, I might not worry about it at all. Maybe just check
the shims to see if they need to be pounded in a little harder.

Just finished sending you a lengthy reply. Apparently it didn't go
through. It's now 3:45 AM. Will try again later when I get up this
morning or whenever. John

Finally I'm getting back to you. Bought a century old half cape on the
south shore of Boston. Turned out to be built in 1743. Am a retired
architect. If possible, get yourself a copy of Ramsey-Sleeper's
Architectural Graphic Standards from a used bookstore. Firstly DO NOT
APPLY TO REGISTER IT AS A HISTORICAL DWELLING. The assistance you'd
get for restoring it is not worth the controls or restrictions that
they impose. When I got my place, there were indications it was moved
to that site. All walls, ceilings were plumb. Floors were buckled,
about a fist deep in the center on one side of the building. The
original crawl space was furrowed out. I furrowed even more. Mounted
steel beams & posts about 2' in from the perimeter and jacked it 16"
higher. That way topsoil could be graded away from the house. The
original foundation was 2 channel fieldstone & brick. It was the only
dry (dirt flr) basement in neighborhood. I redid it the same way
replacing the middle tier with 1/2 thick masonry. In that way allowing
the 2 air chambers in the foundation wall acted as insulation. It kept
the visual of the house in tact. As a result of the jacking the floors
did pop back. That was good. It loosened the forged square nails for
reuse. Replaced the worn out subfloor. Numbering each floorboard as
it was removed. All floors were pumkin pine. When replace, were
caulked with 1/4" hemp. Walls were horsehair plaster. Replaced with
layered drywall to maintain same thickness. Insulated at the same
time. House was built in balloon construction: full dim studs from
plate to plate; 2nd floor joists were mirtised & tenoned. As a result
it was easy to run insulation from roof to foundation. I became a
familiar sight at all local building wrecking yards. At the same
time, Boston was developing the Government Center. I was involved in a
lot of that design. A GC(general contractor) had removed 2' of paving
in Beacon Hill. He found exterior hickory paving bricks. You know who
got most of them. When sliced, they became kitchen flooring & driveway
At the time of insulation, ran copper tubing for 2nd flr heating.
3-zone steam, mtl bsbd on 2nd; ci on 1st. Put in horizontal AC in
attic. Historical perservation would have not allowed any of it.
Original house was 39-7 front 37-9 d. Final was 39-7 f x 81-7 d.
Replaced 32 windows. Added 16x20 kitch, fmly rm, lndry, rear stairwell
& 2-car gar with apt over. Completed kitchen was horizontal recycled
redwood wainscoat. Original matchstick resquared became cabinets.
Cupboards were rescaled Tavern signs. Replaced rear central hall
(4-11w) wall with outswing french drs/sidelites. Front dr was
3-10x7-0. Added collonade across front of house; L shaped glassed in
pergola to inner back of house. It got a 9-circuit electrical system
and copper lines throughout. Except for the furnace, Ac, wh,
appliances, everything used on the house was used. The house was in
Architectural Record for the Bi-centennial.

Thanks for the replies everyone, it was very useful. As a previous poster
mentioned it's not looking like something that needs an immediate remedy so
I've decided to just keep monitoring it for now.

Gerald