Drilling Holes in Joists
Drilling Holes in Joists
(OP)
We are trying to work out an optical alignment mount on a mezzanine up close to our ceiling. We are looking for attachment points to which we can attach a rigid fixture, preferably one not attached to our floor. Our floor is plywood and not very rigid. People should be able to walk around without affecting our alignment.
One possibility is that we attach cross braces to our ceiling joists. The cross braces keep the lower parts of our ceiling joists from moving side to side. The joists are rigid up and down. We attach our fixture!
I am mechanical, not architectural, but as far as I can tell, the joists are standard ones, welded from steel angle and bar.
How safe is it to drill 1/4" holes in the joist flanges?
JHG
One possibility is that we attach cross braces to our ceiling joists. The cross braces keep the lower parts of our ceiling joists from moving side to side. The joists are rigid up and down. We attach our fixture!
I am mechanical, not architectural, but as far as I can tell, the joists are standard ones, welded from steel angle and bar.
How safe is it to drill 1/4" holes in the joist flanges?
JHG






RE: Drilling Holes in Joists
RE: Drilling Holes in Joists
Thanks.
JHG
RE: Drilling Holes in Joists
I recommend that you get a hold of the joist tag (usually a thin and small aluminum strip) attached via a wire to the end of joist. It should have identification of the joist size, manufactures and joist mark number. Also measure the depth of the joist and the span. Also make free body diagram of the joist locating the concentrated load.
Call th joist supplier and provide them with the above data. They will give you a reading if you can add the load, or if you have to beef up the joist and they should provide you with details.
Another simple solution is to hire a local structural engineer and have him run all of this down for you.
Good luck
RE: Drilling Holes in Joists