I pre-drill to the OD of the screw shaft. Then the threads are fully engaged without splitting the wood. In a very heavy fixture I'd try to figure a way to screw the fixture mounting bracket through the box and into the beam. Then the fixture is hanging by more than the 10-32s in the box.
#59292 - 12/01/0509:10 PMRe: Laminated beam and fan box...
What it appears is, that none of the methods used with standard construction is correct, the recommended method will be by each indivisual manufacture of the lam support, we were working at a site one day when a company engineer was there explaining the proper way to support mechinical equipment including ceiling fan's
Here is a good site to look http://www.boozerbeam.com/techsupport.htm It is a supprise to find out that the top of the Lam is where they want it supported not at the bottom, and also notice the critical areas.
#59293 - 12/02/0512:01 AMRe: Laminated beam and fan box...
Assuming properly drilled pilot holes, would installing one on the bottom of a glue-lam provide the full support rating? I'm envisioning the laminations separating as the screw enters the piolt hole, and the threads possibly not engaging the wood around their whole circumference.
Just what are the dimensions of this beam where you are installing the box? If at least as wide as regular 2x lumber I can't see a problem. Even though it's laminated it can be considered as solid as regular lumber so I don't think you are going to have a problem with it separating. It ain't going to come apart.
LK, I don't think what you provided applies here, this really isn't that heavy.
75 or 100 lbs is far more in weight than the typical ceiling fan found at box stores. I have hung many Hunter Originals that were up there though. If we are that worried that the wood screws would come out of the lam, perhaps you could provide an additional support by using a standard Simson strap that wraps around the beam at the point where you are mounting the box. The additional side screws or nails of the strap will provide the strength to hold the lam. Now drill and tap the Simson tie to hold your box with a substantial hole such as maybe a 1/4- 20 thread. Use a fan rated box like the one in the picture.
#59295 - 12/02/0507:25 PMRe: Laminated beam and fan box...