So just to close this out.

Based on the ideas that you all passed my way I've finally got that sucker
up there and am using it.

BTW: Hitting a punching bag for 15-20 minutes is TOUGH, my arms feel like
they're gonna drop off.

Anyway, so basically what I had to do was place stringers between the
ceiling joists to about the 2nd one over from the hanging point (5 joists
are tied together with stringers), from there I also placed joist to rafter
stringers to tie the ceiling to the roof. It was after placing the
stringers to the rafters that the ceiling finally stopped moving

At this point I might go back up and add a second collar to the rafters,
strengthening those joints, then add another stringer set from the middle of
the joist span to the rafter


"Eigenvector" wrote in message
news
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?