What is the story on drilling through wood beams? 5" thick 12" high.

you lost me Redsy

can't i just drill it?

To completely confuse things:

Hixson (Mining and Electrical P.E.) said "Always drill dead center"...

McClung (Archetect, GC) says: "Drill in upper third near endpoints, lower third in the middle of the beam..."

I say... "Drill wherever is most convenient..."

Heck, in my mood right now, I'd take a sawzall and completely remove the sucker...

sparky,
I think some limitations are placed on drilling beams. I was retrofitting some recessed cans, and when I cut a small section of ceiling away to notch what I thought was a floor joist, I noticed that it was 5" wide. I opened up the hole some more and it appears to be a long beam. I don't thing it's OK to drill through, but I don't do much new residential work, so I thought someone here would know.

sparky66wv,

relax, and ask your girl for a massage.

[This message has been edited by Redsy (edited 11-03-2001).]

My mistake. It was an engineered wood product beam. In case it makes a difference.

[This message has been edited by Redsy (edited 11-03-2001).]

Better be careful what you drill! Structural engineers get real up tight when you make Swiss cheese out of their design. In housing I think it is drill the center but only in the outer third. I could be wrong, as I don’t do housing. In commercial work you better get the blessing of the structural engineer before you drill any structural member. God help you if you drill a glue lamb! It can be done but only with good reason and close structural supervision.
I did a restaurant a while back where the entire dinning area roof structure was wood framed with plywood sheeting on top and exposed tongue and groove below. We were not allowed to drill ANYTHING! No way forget it not in this lifetime. Ok, how do we get all the electrical in?
Well, we ended up having to run everything through a little void created by the plastered underside of the rafter tails around the perimeter. I’m talking multiple ½, ¾ and 1”conduit. At each point where there was a fixture or device we turned into the building parallel to the framing members. What a pain!
Moral of the story: Don’t drill unless you have permission. You may be paying some carpenters to replace their work.

Nick,

Glue lamb?

Maybe it is spelled as a compound word. I don’t know. (I am a terrible speller) They are very common in this part of the country in light commercial buildings. Mostly, but not limited to, concrete tilt ups. If you haven’t seen one they are made from multiple layers of wood pressed and glued together. They are used as main structural support

Redsy,

The 'Lam' is as in Laminated.
Multiple layers of pressed wood, plywood etc. Strong stuff. Where is this beam? I doubt that you drilling a small hole through it will weaken anything.

Bill

[This message has been edited by Bill Addiss (edited 11-04-2001).]

I do a lot of residential these days, which is'nt my first choice , but feeds the fam. I'll typically drill out with milwakee self-feed bits. If the hole is large enough , and it has obvious space around the conductors, it is not 'bundled', the rationale being heat captivated. So i drill big holes, especially home runs back to the MDP. The thing about the self-feeds & a right angle, is they are straight, the pull is without strain, goes smoothly. One of the most congested area's, as well as site specific, is the kitchen. As bearing walls are usually 2x6", a 1 1/2" centered run is OK. Besides, the plumbers are usually the first focus of any structual meddling. Most carpenters i've asked ask for a centered hole in beams.

In drilling standard wood beams, the rule of thumb out here has been to keep the holes within the outer 1/3 of the spans. Most inspectors like them within a foot of the supports. Drill through the center of the span, and you'll be buying somebody a new beam.
Gluelams, as used in our tilt-ups, are seldom drilled, as you can normally pass under them.(They aren't as strong as they look, they only hold up the roof)
For Engineered wood products, such as TJI joists (the waferwood or plywood jobs with a top & bottom chord) we always have to contact the manufacturer for their requirements, as they can vary.

Bill,
The beam runs from the rear of a townhouse forward. I don't know how long it is, but I drilled a 5/8" hole about 2-3" from the bottom, and about 24" from the end. I doubt that any appreciable harm was done, although during construction I'm sure that everyone can't just indiscriminately drill as they please. However, I wanted to get some opinions for future reference.
Thanks, everyone.

[This message has been edited by Redsy (edited 11-04-2001).]

Electure,

Are we talking about the same stuff?
http://www.apawood.org/glu_level_b.cfm?content=prd_glu_main

Redsy,

Yes, it looks like you really can't just drill any size hole wherever you want it.

I found some good info: (get PDF at end)
http://www.anthonyforest.com/stockfaqs.htm
(cautions to read the following before notching, drilling, etc.)
**************************************


This comes from a 6 page PDF file that looks pretty good entitled: "Field Notching and Drilling of Glued Laminated Timber Beams"

Note:
The construction of these things are not uniform, so there are zones that are definitely better than others.

Get PDF File

Bill

[This message has been edited by Bill Addiss (edited 11-04-2001).]

When requested to replace said beam, I would simply request to see my contract...

There are advantages to the "no contract" way of doing things...

I've drilled 2" holes in glue-lam... If they didn't like it they can find somebody else...


Muahahahahahaha! (Evil laugh)

Wow!

That's really different than plain old Wood!

Al,

That's a interesting PDF file. isn't it?

Bill

Bill,

THANKS!
That was EXACTLY what I needed.

Redsy,

It looks like you drilled in a good spot!

I've only done custom resi work and many times these beams are waaayyy oversized and drilling wouldn't be as critical, but it is good to know this information anyway. They probably oversize just to be sure and don't care as much about cost because they are not buying a lot of them. I'd imagine that in situations where many beans are needed (many similar structures going up, Condos, Townhouses, etc.) for economic reasons, they would be sized more closely to the load served and therefore have less tolerance to field modifications.

Bill

[This message has been edited by Bill Addiss (edited 11-04-2001).]

This is from the 1988 UBC. I do not have a later version but should be similiar.

Notching and boring for wood joists that are structural members:

Notching can't be done on middle third of the joist.
Notches on the end can't exceed 1/4 the joist depth.
Notches in the top or bottom between the end and 1/3 joist length can't exceed 1/6 the joist depth.

Bored holes can't be within 2" of the top or bottom.
Bored hole diameter can't exceed 1/3 joist depth.


Gerald Powell

Let me reword my post, Bill.
Yes GLB's are strong, but they're sized site specifically for their job of holding up the roof. Any added weight and/or modification to them (drilling) must be sent to the structural engineer for approval.
Some people will look at their massive size, and figure that they can hold up anything, but it's just not true.
I've only seen a couple of them with holes bored through, and I'd imagine that these were done without approval.