BP wrote:
wrote in message
oups.com...
We live in a small cheap 3 bedroom ranch built in 1976. We are the 2nd
owners, it's our first house.
We've recently noticed, while doing some work in the basement, that
about 2/3rds of the floor joists in the basement are twisting on the
main beam. They are no longer perpendicular on the beam but are on an
angle. / , not | , when viewed on end. Some are worse than others.

There are a few slightly saggy spots in the floor upstairs and it's
starting to squeak.

A few more details:
1) The joists are 2 x 10s, 16" on center.
2) The span is 12 - 13 feet - because of a stepback in the front of the
house one end is 24' across, the other is 26'.
3) Metal X bracing is installed at mid-span for most joists, but is
missing where ductwork is and in a few other places.
4) The joists do not overlap each on the main beam, they are butted
against each other and a single plywood gusset of about 1/2" thick, 6"
wide, and 2 feet long --stapled-- to the joists across the joint.
5) No toenailing is apparent where the bottom of the joist meets the
beam.
6) No blocking was installed where the joists meet the main beam.

My questions:
1) Is it possible to straighten the twisted joists? If so, how?

It can be done but don't expect perfection. You should have solid 2x10
blocking over the beam and between the joists anyway. In Mass this is
required by code now for fireblocking. You cut 2x10 blocks 14.5" long and
get them in place on an angle and then beat the hell out of them to drive
them in parallel with the beam and blocking both the front and the back
joists. You may need to cut them shorter on the badly twisted joists. If
they wont drive in they wont drive in. Cut em. You can use an 8 foot 2x8 or
2x 10 to use as a lever to twist the joist back close to straight, or pipe
clamps or come-alongs or anything. This is a two person job and not for the
dainty. By the time you are done you should be exhausted and have absolutely
no aggression left in you!

2) Should the joists be sistered with more 2 x 10 across the main beam
or put in more plywood gusset before putting in blocking?

No. Unless you see physical evidence of a break or a large crown or dip
(1/2"+). "Checking" (long cracks going with the grain) is normal and not
usually a structural issue. 2x10 can easily span 14' on a first floor.

3) Can you block or sister with that small plywood gusset in place or
should it be removed to get full access to the sides of the joists?

No need to remove it. Drive some more nails in it.

4) Will jacking anything up be required? What gets jacked? It seems
like a bad idea to jack the joists that are at an angle as you may roll
them over more.

Can't comment on that sight unseen. You need to have a pro look at the whole
structure.


The more information you can give me, the better, as we decide what to
do (and who will do it - we do a lot ourselves but this may be
contractor territory).

The most likely cause of the squeaking floor is the metal bridging. It is
notorious for this. I have done several replacement jobs in my area to solve
this problem. Cut out all of the metal bridging and replace it with wood
strapping for bridging. You can leave part of the metal that goes under the
plywood in place and just bang it down flush with the joist.
After that run a bead of construction adhesive down the joint between the
joist and the plywood on each side wherever you can reach. Press it into the
joint with your finger. Stay off the floor for at least 8 hours.


We would like to punch both the builder and our building inspector
right about now. Both were idiots - the builder butchered a lot of
stuff and the inspector never caught it, and we were too green to know
what we were looking at.

Everything you explained was "state of the art" for the 1970's. They don't
build em like they used to, and that's a good thing.


Thanks very much,
Liz


I can see straightening one that is free but how do you do it in this
situation? The subfloor at least if not also the finish floor is
nailed into the tops of those joists. Any straightening has to bend
and pull on those nails.

Harry K