What is the 'correct' way to hide steel jack posts inside a 2'x4' stud
wall? I see lots of online suggestions about 'boxing-in' a post, but
could find nothing on building a wall around a post. Assume the post
is 3.5" (or less) in diameter.
Obviously, the top and bottom plates cannot pass through the post. Do
you simply build two separate walls on either side of the post and
then drywall over the top to make a smooth, continuous wall?
Bonus points: Is it possible to build a 90 degree wall such that the
jack post is in the corner where the walls meet (vs. the 3-stud method
if no jack post was present)?
I built two wall sections and butted them to each side of the post. I also
used a temp scab board at the top and bottom of each side to make sure they
were straight before screwing them to the floor and the ceiling.
I see no reason you could not do a corner in a like fashion as long as the
inside corners met. Now I will need to think about how one would finish the
OS corner on the other side. :)
These wall aren't load bearing. They just need to hold the drywall securely.
You could hole saw the top and bottom plates (very accurately) and cut
the hole in half (if 3 1/2", it would just fall in half), then fit
these to the post. I'd consider leaving an access hole to the jack
part just in case, but I guess you could do that as needed down the
re: "Do you simply build two separate walls on either side of the post
and then drywall over the top to make a smooth, continuous wall?"
Yes, but you need to make sure you compensate for the gap so that your
studs still land 16" OC. If you don't, you'll have unsupported drywall
seams or more seams than needed.
re: Bonus point question...
If the post is in the corner, what is going to support the 90 degree
drywall joint? If the 2 sheets are flapping in the breeze, I'd assume
the joint is going to crack eventually.
What if you tried this:
Assume 1/2" drywall, for purposes of this discussion.
Position one wall such that it is flush with face of the post.
Position the other wall to leave a 1/2" gap between the post and the
On the wall that is flush with the face of the post, squeeze the
drywall in between the post but "behind" first stud of the other wall
so that the post provides support for the drywall. Maybe even drywall
that section of the "flush wall" before framing the other wall so you
can position the second wall correctly.
I don't know if this will come out correctly, but...
O is the Post
D is the Drywall
||| is the Stud Wall flush with Post
= is the Other Wall
In this manner, your corner should have sufficient support to prevent
Thanks for the help, I'll take these suggestions under consideration.
Using the scab as a guide sounds like a good idea...I was planning on
snapping a couple of chalk lines to mark the position for the bottom
plate (snap around the post)
I'm putting a door between two of the posts, so the 16" O.C. is
probably not such an issue. That particular wall will end up being
about 6' long so it's going to be a real mess of studs (kings, jacks,
cripple, butting against posts, and end-wall).
For the corner, I'm hoping that I have a few inches (5 should do it)
to turn a corner 'normally' and then simply embed the post in a
straight section of wall as described above. That would ensure that I
don't have drywall joint failure (I hope).
If I don't have room, I'll try one of your solutions. To make it
easier, the outside of the corner will be in a utility room and does
not need to be finished.
As somebody else said, just frame it w/ 2x6 instead of 2x4; won't be
enough difference in material cost to matter and saves much other pita
Ditto on that poster's remarks re: jack post as well.
Oddly enough, I've actually got space to do this in one case. I'd
still have to use a hole saw for top/bottom plates and split-fit
around the post, but at least there'd be a continuous surface.
For the other instance, there just isn't any room to put a 2x6. The
wall will already be uncomfortably close to my cleanout/drain.
There are two things working against that idea:
1) My terminology may be incorrect. What I'm calling a jack post is a
hollow steel post that has a threaded cylinder at the top for height
I hadn't even heard of a lally column until today (either nobody
around here uses 'em, or nobody calls 'em lally columns). Perhaps
we're talking about the same thing, only in different jurisdictions
2) The jack posts are already a fixture and I don't see the point of
replacing them. It is likely that they are resting on concrete
footings poured specifically for them, so I'm not sure what the
problem would be (see #1).
FYI a lally column is constructed of pipe or tubing with bearing
plates top and bottom. They are code required in many communities
nationwide. Contractors may order them done as building progresses, or
ahead of time if they have a decent plan set. A jack post does not
have the load carrying capacity of a lally column but in some case it
may not have to. On some projects I have easily made my own with my
building inspector's approval. Any well supply company has pipe of all
diameters that can be code approved. The pipe is given a rust
resisting paint coat inside if it needs it, and the bearing plates
welded on and outer part painted.. The temporary support (jack post,
even) is removed after the lally column is installed on the footing
and the concrete floor is poured around it.
People living in places where concrete blocks on slabs are the usual
construction method would likely know little about lally columns.
Architects and better contractors, though, will be quite familiar
with them in most other parts of the country.
_WAY_ over-thunk for the need. Simply fit the wall framing in the space
between the columns and fasten to the floor w/ tapcons or
powder-actuated nails and the overhead structure (joists in
perpendicular, blocking if parallel). Done.
Well, the thickness of the columns is what it is--if you're intent on a
smooth wall surface that's that thickness plus thickness of the wall
covering is what it's going to be.
If it's >2x4 but less than 2x6, rip the 2x6 is probably still faster
than adding shims but is less of a difference if must, granted.
As for the lally-column debate, all depends on what the actual jacks
are. They can be adequate and if were original construction one can
assume they met local Code (assuming was done as part of original
construction, etc., etc., etc., ...). Many of the temporaries aren't of
much use for more than that.
If it didn't waste too much space. I would do the framing with 2 x 6's
since the price difference is worth the time saved. I am not a big fan
of jack posts except as temporary supports, so a lally column would be
If 2 x 4's are absolutely necessary, then consider a lally column made
from schedule 80 pipe with the appropriate diameter to fit the space.
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