Simon wrote:
On 23 Aug, 21:31, "Cash"
wrote:
sm_jamieson wrote:
My structural engineers plans involved a timber infill into an old
tapered flange RSJ.
I cut the timber infill to be quite a good fit into the shape, but
after tightening up, there is a small
gap (2mm) between the timber infill and the RSJ.
Is there any glue / substance that sets fairly incompressible, that
I could inject into the gap
so the load is not purely on the bolt holes ?
Come to think of it though, new timber always shrinks, so a timber
infill that is initially wedged
tight would probably loosen anyway, so maybe I'm worrying about
nothing.
Simon.

For what reason is this "timber infill" being fitted into the RSJ -
is it to fix floor or ceiling joists too, or just to box in the RSJ?

If it's for a joist/rafter, then the usual method (in my day) was
simply to place the thing inside and resting on the bottom web and
use a Hilti cartridge gun to fix the thing (they were never cut to
shape and never moved after a few Hilti nails had been used,

If it's to box the RSJ in without any load bearing, simply cut the
thing slightly longer than the space between the webs, and using a
bloody great hammer, just bash it in, and fix the covering to it - I
used to use the odd Hilti nail in the centre of the timber on long
runs 'just to make sure' and never had one fail (with or without the
Hilti nail.

If it's for any other reason, please do tell.

Cash

Its to hang a joist off - struct eng spec is timber infill both sides
and long legged speedy hanger
wrapped over the top and nailed to both sides.
Issue was - the RSJ has tapered flanges so the "rest the infill on the
bottom" does not work structurally
since the bottom is tapered, and the force encourages it to slide out.

No it doesn't, the taper over the width of the web isn't steep enough to
slide out under the weight of the joist as it's vertical load - just skew
nail the joist to the bearer with a few long nails and that will hold it.

Question is structurally, are the bolts just there to hold the timber
in, or are they to bear the force ?

Just there to hold the timber, the web stops it from falling onto the floor
and a few Hilti nails will work just as well, and a damn site quicker - and
if you really want to bolt the timber on, just fire a few Hilt bolts into
the steel, drill a few holes to suit those positions in the bearer and bolt
the thing on. Think about it!

I will probably knock some steel shims into the small gap under the
timber, just to be thorough.

Not needed, but if you feel as if you need a few wedges, timber one will do,
and be less likely to slip off the RSJ - remember, steel will slip off steel
fairly easily!

Cash