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Drilling roof truss

chris kennedy

chris kennedy

Sawhorse
Joined
Oct 24, 2009
Messages
1,535
Location
Miami Fla
First, Happy New Year to all!

I need to drill a ½" hole in a vertical member of an engineered 2×4 roof truss. This would be to allow the passage of an < ¼" steel cable for a luminiare lift system.

Is this acceptable? Applicable code arts appreciated.

Thanks

 
R802.7.2 ...except where permitted by the manufacturer’s recommendations or where the effects of such alterations are specifically considered in the design of the member by a registered design professional.
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I would expect a RDP to readily sign off on your modification. Check with the truss manufacturer.
 
Chris, correct the alternative is to provide an engineered design. Contact the manufacturer's representative.

Could also search their site for approved repairs such as "Mitek repair details".

There is also a site that sells inexpensive and quick pre-engineered metal plates for repairs permitted by the AHJ.
 
I agree that the engineer that stamped the original drawing should approve alternations, realistically, I don't how that I could be concerned with it in the field. Just curious why you must make the hole anyway?
 
Agree that technically the rdp must sign off, also agree that such a small alteration probably won't be a big deal. Question is the weight of the object and will it exceed the design load of the truss. Probably not but if it needs a steel cable to carry it that might be worth a quick double check. Probably a question the rdp will want answered too.
 
I wouldn't be concerned about it. Just stay a foot away from any gussets. Why so big for a cable that's less than I/4"? If the cable will be sliding back and forth, you might consider a sleeve.
 
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fatboy said:
Just curious why you must make the hole anyway?
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Dead center of where I need to place 2 pulleys for the lift. I spent 4hrs there Tues trying to find an alternative for this craptacular design.

Sifu said:
Question is the weight of the object and will it exceed the design load of the truss. Probably not but if it needs a steel cable to carry it that might be worth a quick double check.
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Cable needs to pass through the hole without contacting the truss, just a hole, no load imposed.

ICE said:
Why so big for a cable that's less than I/4"?
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Need wiggle room as the cable cannot contact the truss.
 
See if there's a knot that can be punch out, just kiddin!

Why can't something be attached to the center support?

I don't think the designer would have a problem with it, get his approval.

Pc1
 
Props to you for asking the question ahead of time, instead asking forgiveness at the the time of inspection.
 
fatboy said:
Props to you for asking the question ahead of time, instead asking forgiveness at the the time of inspection.
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Knowing the nature of this project, I'm betting it's not going to be inspected nor a permit obtained for it. Something I normally don't agree with but in this case I certainly don't see a reason for a permit nor inspection.
 
Drilling a hole would require the OK from the truss manufacturer. If the lift system is for anything other than lights, I would be concerned about overloading the truss as well.
 
Agree with the above. Truss manufacturer or RDP. On a new home the manufacturer will probably be easily identified and their Engineers can sign off.
 
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