I am remodelling my house and have installed a doubled 9-1/2 x 1-3/4 microlam beam to replace a load bearing wall (glued and nailed together). The beam is cut into the joists for a flush ceiling. I need to run a 2″ drain line across the beam (perpendicular) and wonder if I can bore a hole this large in the beam. I have seen conflicting information as to how large a hole I can bore into a beam.
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Each manufacturer publishes detailed instructions on where & how an LVL can be drilled. Generally, they'll spec within the middle third of depth and the middle third of span as drillable. Two inch is often the maximum diameter but is a function of the beam depth. No square or rectanular openings are allowed. Point loaded conditions or cantilevers, all bets are off. What brand LVL do you have?
Al
Al and Jeff -
To my knowledge, NO manufacturer has charts or instructions on where LVLs can be drilled. They do it for I-joists, but not LVLs.
The only way you can find out whether or not they're allowable is to contact the manufacturer or one of their reps who have the tools and ability to analyze the situation. Start with whomever you bought the beam from, and see what they tell you.
I can almost guarantee that it won't be allowed, even though you provided no details about what the beam carries or the span. You're removing more than 20% of the beam's section by drilling a 2" hole. (Or more, if you need more clearance) Unless the beam span is short and/or way over-designed, it won't fly.
I find television very educating. Every time somebody turns on the set, I go into the other room and read a book.
Through a little further investigation on the internet, I went to Georgia-Pacific's and Boise-Cascade's websites and found some tables, identifying hole size and placement. G-P says 1" max. while B-C says 1-1/2" max. Since I need 2" I will have to route my drain line around the beam, but I will be able to run my electrical through it!
Thanks for the comments.
I've seen up to 1 1/2" hole that type of beam,the sparkeys are supposed to know where to drill their holes, but watch out, some times the dude wont get his step ladder, and puts the longest bit in the drill, so he can get 'em while standing on the floor, then you have a hole 1" from the bottom. Some inspecter might call it a notch.no turn left unstoned
Hi Boss-
The brand floor system I work with is Willamette. Yes, they've been bought out by Weyerhaeuser, so the Willamette name may disappear. For now though, it's the one I know and love. Their StructLam design guide, http://www.wii.com/StrucLam.pdf, provides on page 22 a "Guideline For Fielding Drilling Holes In StructLam" which is what I pulled my info from. Weyerhaeuser, the king of engineered floors, also shows the same info in their design guide, http://www.trusjoist.com/PDFFiles/2020.pdf, on page 18. Ideally, I feel LVL shouldn't be drilled at all. The loads are often more substantial than for I-joists and they're usually single or ganged members rather than repetitive. Plus, we all know how closely drilling / cutting instructions are followed on I-joists. But sometimes, ya just gotta have a hole!
Al