On Jul 2, 6:03 pm, "Eigenvector" wrote:
So I posted a little bit ago about hanging a punching bag from the rafters.
I have the bag on a fixture mounted to 2 rafter beams (the rafters are roof
trusses, 2x6's). The bag is a 110lb bag, hanging from an eyebolt . The
issue that I'm seeing is that when I punch the bag, the whole ceiling is
moving. I don't mean shifting off its mounts of course, but rather I can
see the ceiling drywall moving back and forth and rocking in tempo with the
bag.

It's not like I'm Rocky Balboa or someone, but I'm a pretty strong guy and
110lbs is a lot of weight. So I'm looking for some advice/options for my
concerns. My concerns being that I'm afraid that if the ceiling is moving
enough for me to see, that means the whole structure is under way more
stress that it can take. But what to do about an object that weighs that
much but has to hang from 9 feet in the air. The rafters in my house are at
exactly the right height.

Could I build up the rafters at the location where its suspended, add a
second 2x6, add a lot more cross bracing between the two rafters its hung
from, something like that. Admittedly I didn't do a lot of mod to the
hanging point, not knowing how it would respond I chose to take it slow and
see if this was feasible or not.

Right now the eyebolt is hanging from 2 2x4's with a 1/2 plywood sheet on
top across 2 rafter beams. I believe MeatPlow offered that suggestion up
last time I posted this. Give a little more effort I could make a better
suspension jig, maybe 3 2x4's (hole for eyebolt in middle board), 1/2
plywood to tie them together on top.

I don't know, what do you all think?

EV-

last time you posted I told about my experience with a heavy bag hung
from a patio cover with 2x4 joists....when my kids (10 & 14) & friends
punched it the patio cover shuddered & shook. By the time they were
14 & 18 they have become less interested in it until it bit the dust
when a friend tried to ride it.

If the patio cover had been drywalled I'm sure I would have been much
more concerned.

You your case I'd be concerned about working that drywall and the
drywall to ceiling joist connection.

Sistering extra 2x6's might be helpful but I thnk having a mechanism
for the trusses to share the load is more important.

Since you ceiling / roof framing is a truss system let's use the
proper terminology......the bottom member or bottom chord is the 2x6
that the drywall ceiling is nailed to?

I would block between adjacent bottom chords, I would screw a plywood
skin to the top edges of the blocking & the top faces of the the
truss bottoms chords. I suggest using screws because oyu can remove
the system if desired and you'll get a tight more secure assembly with
screws rather than nails.

I would suggest #10's ~2" long (min)

Spreading the load over three trusses that have their bottom chords
blocked. will really help the situation.

I don't know how long or wide a plywood strip you can install but you
might consider stiffening the plywood with 2x4 in the "across the
trusses" deirection. The screws into the bottom chords wiil stiffen
the plywood in the other direction.

If you're feeling confident you might consider construction adhesive
but that make it very difficult to modify or remove the retrofit.

cheers
Bob