Half of our basement was dug down about 6 inches more than 30 years
ago. I just pulled down some wall panelling in the dug-out section, and
discovered that there is about a 4 inch gap between the bottom of the
foundation wall and the basement floor. I can clearly see earth fills
Here are a couple of photos of the gap:
The house was built in the 1920s, and the foundation is poured
concrete. The basement floor is poured concrete. The earth is very
sandy, and we do not have a problem with water via the gap. There are
no cracks in the foundation wall, nor are there cracks in the exterior
brick of the house to suggest bad settling. I have only uncovered a
small section of the walls so far.
I've had a couple of contractors in who suggest an expensive "proper"
addition of footings. Another contractor suggested the earth be dug out
several inches past the exterior of the foundation wall, and
back-filled with concrete to make a sort of 1/2 footing. Or I was
considering just filling in a few inches of concrete on the inside to
prevent the earth from spilling inwards. But I don't believe that will
add any structural support.
Do I really need expensive several-feet deep footings with weeping
tile, etc., to replace the earth that hasn't moved much in all this
Any opinions are appreciated.
You can hire a contractor to jack up the slab, (Google, concrete
jacking.) If you let it go as is and build the wall again use treated
lumber on the bottom plate. This floor job was done wrong from the
beggining, because the slab was never pinned to the footing, wall or
laid on a ledge. This will be a costly project no matter which way you
It's not all that uncommon in older houses to have had someone dig the
basement deeper. Often these had dirt floors anyway, or at least a very thin
(1-2 inch) concrete floor. I've seen where they've taken the floor below
the top of the footer, leaving a 3-4 inch 'step' at the wall. Since your
wall does not appear to have a footer, they've dug below the bottom of the
Bringing this job to code will be an expensive undertaking since it would
require excavating, and probably building entirely new footers and
foundations. If as you state, the work to lower the basement floor was done
30 years ago, and you haven't had any problems with water leaking in , or
settling you could just close it ack up and hope for another 30 years.
A general contractor is going to have to do it to code - pulling permits,
etc. Something less than code, such as what you've describe is probably not
going to be all that much less expensive, so think long and hard before
taking the short-cut. Particularly if you ever plan to sell the house.
There may be disclosure issues with knowingly having 'fixed' something and
not brought it up to code. Leaving it as is would be less of an issue since
it isn't uncommon to have things in older houses that aren't up to current
code - and know they exist (such as plumping of electric issues).
How much perimeter wall are we talking about? One or two story house?
Maybe you can find an engineer & a contractor with a little
Perhaps the existing condtion could be improved piecemeal by digging
away a small section, backfilling with reinforced slightly expansive
concrete....you'd have to have the solution engineered & ok'd by your
local building dept. The work could be done one section at a time.
That wall is probably pretty stout...it's just missing a proper
here is a link to the screw type underpining referred to by another
depending on local conditons you might get away with a reasonable
I think the stuff about bringing it "up to code" is nonsense, in this
case. This isn't a new house, this isn't new construction, addition,
etc.. I'd be surprised if there even was a "code" to speak of in this
case, which means that whatever your building inspector says is okay,
is okay, and anything else isn't. If you involve your building
inspector, that is.
If this has been 30+ years, with little to no movement in that earth, I
think starting in on a massive excavation and foundation job would not
be called for.
First, do you know how thick the wall is at that point? It could be a
simple 8" thick wall that ends abruptly. Or it could have a thickened
half-footer edge (i.e., a footer but only on the outside of the wall,
so not visible from inside).
Your idea of just adding some concrete at the corner of the wall and
floor is done pretty often around here, as far as I can tell. We had an
offer to do our garage basement this way (but we didn't end up doing
that). It would be much cheaper than any alternative, and likely work
just fine -- get some more opinions from foundation and concrete
workers. It involves first drilling into the floor and bottom of the
wall, and inserting rebar pegs. Then you build a small set of forms,
and pour a beam (maybe 1 foot high by 1 foot thick) around the edge.
The rebar pegs help bond it to the wall and floor. The purpose is to
take some load off the soil under the wall (via the rebar pegs,
transfering load to the 1 foot wide new concrete base), and to keep
that soil from moving. With a concrete pump, a team of workers could
have this done in a few days.
There are two ways of looking at this. First and properly, you're
pretty well screwed. It should be immediately fixed and fixed properly
-- and it's be unbelievably expensive.
The second way of looking at is is that it hasn't moved in the last 80
years so it ain't going anywhere .. esp. since you don't have water or
frost at that level.
Personally, I thing the biggest problem you would have is something
undercutting the wall and having it look support. I am not an
engineer, so please disregard my advice and I do not intend to tell you
what to do, merely what I would do if I owned the house.
I would put a 2x12 about a foot out from the wall. I would then drill
holes 6" out from the wall and drive rebar a foot two down, say every 2
feet. Then put a couple of piece of rebar running parallel to the
wall, connecting the pieces I drove into the ground. Then I would fill
the area between the wall and the 2X12 with concrete. That (and the
rebar) might keep the concrete wall from being undercut.
|~~~~~ | top of new concrete
| | new wall
dirt } | |
} | |
But consult someone smarter than me before you do anything like this.
I don't want to be responsible for your house falling down.
The building has been this way for 50 years. what problem are you
trying to fix? is it settling? why would it start in the next 50
years? you can't bring the building up to code (lack of footings is
just one item in a long list). besides, even if you did, your return
at resale time would be pennies on the dollar.
if it was mine, i'd stand up a form board and cover the exposed sand
with some concrete. provided the foundation is relatively plumb,
level, and square and not moving, spend your money on windows,
insulation, siding, kitchens, baths. might as well flush some money
down the toilet as retrofitting footings on a perfectly good foundation.
If it hasn't moved in 30 years, the chances are it's not going to,
at least until the next earthquake, flood,
If you WANT to fix it, there is a range of choices, trading off
how much space in the basement you're willing to give up,
how much money you're willing to spend, how much time and effort
you're willing to put in, and whether you want to involve
your local authorities and/or contracters.
If you trench just a few inches into the slab, and pour
a knee-wall up against the base of the existing wall,
you only have to make the knee-wall in a way that
will keep it from rolling. THat will be structurally
sufficient until and unless the soil outside the
wall actually liquifies, which is unlikely. It
won't be waterproof, though.
Failing that you could use timber jacks to take the weight
off the house, drive pilings sideways into the dirt under the
existing wall, and excavate 2' to 4' sections and pour footings
under them. (In that scenario, you'd use expanding concrete)
How big a chunk you do at once in that case depends on
how big a hole you think the wall will span without
support while you're working. I don't think I'd be
willing to try that with a rubble wall, but from
the picture, you've got monolithic concrete, right?
This latter is essentially the same thing you'd do if
you were trying to put a window in, but you're putting
them is really low, and filling them with concrete
Thank you for all your opinions. They really helped me make up my
I'm going to call in an engineer to make sure it doesn't look too
dangerous, and if it still looks stable after all this time (which I
hope it will) I'll do as little as possible to stop the sandy earth
from spilling out.
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