What tie should I use to attach joists to a beam sitting on top of the
joist. I know I could put it in flush with the joist and just use a
regular joist hanger , but I would like to put the beam on top. The
joists are 2x6s and the beam is a 4*12.
This is an unusual situation--I doubt there is a piece of hardware
made specifically for this. Simpson strong tie sells heavy duty
twisted straps that would work, though i don't think they are made for
that purpose (google it). If you are dealing with a building
inspector, they might want to see it engineered.
A 'hurricane' strap would do it (the ones for connecting rafters to
top-plates), but you could probably just toenail it.
This sounds unusual, why are you putting a beam *on top* of joists?
A beam indicates it will be carrying a load so the joists would have
to be supported to carry the beam. A 2x6 joist can't even span 10' @
16"OC, nevermind carrying a beam and additional load.
Hope you have an architect or better an engineer involved.
I imagine what the OP is doing is removing a load bearing wall and does
not want to put the beam in the room, but in the attic instead, above
the rafters/joists. I have seen it done before, but never paid attention
to how it was attatched. First, I would go to the Simpson section
at HD/Lowes and check them out. They have fasteners for nearly every
imagineable use-- may find something that would work. If not, you could
get metal "L" shaped plates with a hole n both parts of them and bolt
one to the joist and one to the beam such that holes in each line up and
hook them together with all thread and nuts. Larry
Another thing came to mind-- if you look at the Simpson Strongtie stuff
at the box store, see if they have a catalog there where all that stuff
is located.(They do here) Just because HD/Lowes does not have something
doesn't mean that it does not exist-- just may take some extra time and
effort to get it or special order it. Also see if Simpson has any info
on the web. Larry
I don't want to just hang the beam, I want it on top (because I am
removing a wall below and don't want it to show). The beam will be
supported with blocking at both ends, so the beam will still support
the joists. I looked through the simpson site and didn't see anything
that jumped out at me for this.
If I have to, I will inset it and use hangers, but that will be more
work and the 2x6s are old so they are wider then 1.5 inches, so might
not fit a regular hanger. As for the joist size, the joists are
already there and they are just in the attic over a relitivly short
span, so that shouldn't be a problem
Getting a cutoms welded bracket is probably out of my price range.
Typically the 2x6 ceiling joists would be sitting on the wall top
plates, so it should be a simple matter to sit the 4x12 beam on the
wall top plates so the bottom of the beam is aligned with the bottom
of the ceiling joists. If the issue is that you don't want the beam
to project horizontally the additional 3.5", just cut back the ceiling
joists 3.5" so the beam doesn't project. Be sure that the built-up
posts in the walls supporting the beam are adequate.
No problem, joist hangers are made in a variety of widths, including
sizes for rough lumber.
Now I get it.
Maybe something along the lines of these things
They are cheap enough you could put them on either side of each joist
on both sides of the beam giving you a total of four 'straps' at each
beam/joist intersection. With good size nails pounded into every
available hole would probably easily hold up the joists.
You could probably even bolt the two straps on either side of the beam
and joist. Still I would be wary of such light duty connectors.
Go to a real lumber yard like 84 Lumber and ask them. There has to be
some kind of ready made hanger to do what you want.
The beam will not support anything that is below it. it must be
placed underneath the load for any support to occur. Is this you own
personal fantasy or did you run this idea past anyone with any
experience like a carpenter?? It sound like you thing these hangars
are going to support the load. That is wrong headed in my opinion.
You will need a damn strong bracket if you are doing what I think. You
likely wont' find it on the shelf. If you design the bracket and
provide drawings you can hire a welder/fabricator cheaper than you
might think. Where I live metalworkers are everwhere and every farmer
and mechanic does welding. Everything is negotiable with these guys
and a lot are out of work.
I always want things like this to be many times stronger than actually
needed, but this is not going to require some 1/2" thick steel brackets.
Look at the weight a joist hanger will support vs. how light and flimsy
they look. Larry
On Feb 9, 2:17 pm, email@example.com (lp13-30) wrote:
A joist hanger works with gravity supporting the load from underneath
with multiple nails. Other larger nails also hold the joist in
place. If you want to support the beam it from above then it must be
supported from above perhaps with steel cables and turnbuckles. It
would be more than unusual.
Roof joists or collar ties are not usually large boards but they are
vital to the structural integrity and must be supported from
underneath and they should not be attached to the beam in the way
suggested. Rather, steel cable could be attached to the ridge beam
which could be beefed up would be a more likeley solution in this
No, it is not impossible but a more conventional approach can most
likely be used. If the OP insist one this wacky idea I suggest he
hire an experienced carpenter or engineer to OK the framing design.
and made to look nice with some moulding. That is a more conventional
solution and easier to design and execute.
Say what? Gravity is supporting the load? You claimed a beam had
to be underneath a load to support it. That, obviously isn't true.
The most widely used joist hangers obviously support a load that is
attached to the side of the beam.
Other larger nails also hold the joist in
Go back and read the question. He doesn't want to support the beam
from above. He wants the beam to support the joists that will be
below it. Unusual yes, but certainly possible with the correct metal
brackets and without cables and turnbuckles.
If a beam can support the weight required by the joists, and a bracket
is used to connect them, then it can support the structure whether
from above or below. The obvious and very std joist hangers already
attach to the beam from the side, shooting your whole argument down.
And if that ain;t enough, here's a link to a supplier that has
something pretty close to what he's looking for:
Notice the part about "underslinging joists"?
Like turnbuckles and cables, instead of simple metal brackets? LOL
the OP insist one this wacky idea I suggest he
The beam doesn't care whether the load it's supporting is above it,
below it, or tacked to the side. The only issue is making sure
that the hangars are capable of supporting the load on the joists.
Since these are 2x6s, one assumes that the span tributary to the
beam isn't more than 10'. If the joists are 16" o.c.,
that's 13.33 (call it 14) square feet. Since OP is
willing to have the beam above the joists, one assumes that
it's not a load bearing floor, so we can call it pessimistically
30 PSF, or 420 pounds per hanger.
I don't think there's any commonly available steel with a yield
strength of less than about 20,000 psi, but lets use 10,000.
The easiest way to support the joist is to wrap the strap
around the bottom of it, run it up both side, up one face
of the beam, so there's one strap up each side of the joist,
and hook both ends over the top of the beam. Each half
needs to support 210 pounds. On the other hand we're bending,
twisting, and drilling holes in it, so we'll triple that
value, and call it 630 pounds. Since our cheap-ass
recycled steel bar-stock supports 10,000 psi, that means
we need a strap with a cross section of .063 square inches.
Half-inch strap iron 1/8th inch thick is, conveniently
0.0625 square inches in cross section.
Hmm... common box nails, in sheer, 3" penetration
... call it 100 pounds per nail. which works out
to 6 nails per strap.. That seems excessive to
me, but hell, the point is to make stupid overbuilt...
So put 3 nails slanted one way, 2 the other, up the face
of the beam, and a sixth on on top.
Attach the brackets to alternating side of the beam
on each successive joist, so it won't be tempted
to roll. Put blocking between the joists near the
beam so that even if some nut-case screws a swing
into one of the joists, it can't pull sideways and
behead the nails one at a time.
Goedjn is not an engineer.
Goedjn is an anonymous voice on the internet.
Do your own math.
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