I'm throwing this one out there before I get into trying to fix the
situation in case anyone has encountered this and might offer some
This is a two story colonial style house built in 1990. From some
general observation and measurement, the center of the house has
settled about 1/2 to 3/4". It can easily be seen at the doorways. I've
found that the cause seems to be the main beam that runs the length of
the house (three sistered 2x12s) is compressing at the posts in the
I figured one way to verify the distance of settling would be to use a
water level to compare the floor joist height at the sill to the height
at the beam. I'd repeat this at each joist across the span to get an
One of my major dilemmas is moreso how to correct the problem. Some
initial thoughts were to use jack posts on either side of the permanent
posts to relieve the weight in order to install pieces of angle iron
under the beam at each post perhaps extending 8" in either direction to
distribute the force rather than simply shimming.
Does anyone know if this is a common problem? Is there a way to figure
out if the builder installed enough posts for the span? I'm assuming
the current problem is good reason to assume NOT.
What was the original warranty on the structure? No matter your not the
I would be calling the building inspection people and asking a lot of stupid
Taking this on alone is fool hardy. You might get someone to step up and
Ive used screw jacks and 1/4 inch plate steel , get the steel from a
scrap dealer. A problem could be the footing for the jack as a floor
will lilely crack if you just add another one beside it. Do you have a
screw jack or solid post. Best might be removing the post and insert a
screw jack support in its place. While suppporting it on either side
tempoarily so it doesnt fall.
The existing posts are solid, not screw jacks. I wouldn't think screw
jacks would be up to code in permanent situations. The biggest problem
I see with putting screw jacks in place of the old posts is that the
beam can continue to compress. Perhaps it has as much as it ever will,
but I'd definitely want to get some steel plate under it to distribute
I was thinking of building some supports on either side by stacking
concrete block 2 at a time and using a hydraulic jack. I'd do this on
either side of the existing posts. I am concerned with cracking the
slab though. I don't know how large the footings are. If I can get the
pressure off the existing posts, I can at least shim it to make up for
the sag. At best I'd like to get 1/4" angle iron under it. The other
side of the angle would go up the sides of the beam on either side for
added weight distribution. Then I might install some 3/8 bolts through
the angle and beam for added security.
Someone suggested I get the original builder involved even though I'm
the 3rd owner. Exactly how do I find out who the builder was?
Sounds like not enough beam and/or posts for a house that big. IMHO, it
shoulda been a steel I-beam, or at least an engineered lam or something. You
are right, you need a professional engineer to look at it. Need to see if
the posts are too far apart, if they had adeqaute footers under them, etc.
3/4" sounds like an awful lot of compression- is the beam splintering?
Probably lotsa ways to fix, the engineer will know. Some of the basements I
have seen while house-shopping have had all sorts of kludgy secondary
beams/posts added, or steel gussets added to wood beam. Jacking the house
and adding a steel cradle to catch the weight over a wider area sounds like
a decent idea, but the housing inspector (for when you sell), and probably
your insurance company, will be happier if there is an engineer's stamp on
the working diagrams. Adding more posts isn't that hard, if it won't make
basement unusable, but does involve a lot of dust and dirt from jackhammer
to punch through slab, and mixing or carrying concrete to add footers to
catch the new posts.
I would definitely call the builder in to look, if he is willing. (or have
the inspector call him) You won't get a freebie, since place is 15 years
old, and probably in no danger of actual collapse. But he may be embarrassed
enough to offer to do the work at a cut rate, assuming you trust him after
he fubar'd it in the first place.
2' angle iron will bend. I tried it. Screw jacks are code if they are
strong enough, they have ratings and are custom ordered. You have to
jack it maybe 1/16" a few days, a hydraulic may loose pressure.
That's a decent idea, but this is a newer home in a neighborhood of
homes ranging from 1-230 years old and I can think of only one other
home built at nearly the same time (totally different design however).
RE: screw jacks.. I actually have two screw jacks. I'm wondering if
placing them on either side of the permanent post will have enough
strength to lift the beam enough for shimming. What would be a good
base to use to distribute the force across the slab?. I was thinking of
stacking a couple 2x12 blocks.
I'm actually thinking about leaving it be and just reset all the door
jambs. I'm planning on laying some tile and hardwood flooring and if
I'm going to fix the sagging even a little, now's the time to do it.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.