Point load applied to roof diaphram
Point load applied to roof diaphram
(OP)
A building I'm working on has had some changes per the architect. I now have a point load from a newly added wind girt that was never anticipated. I've looked and looked for a way to resist the girt's reaction of 4500 lbs from wind loading. Not that big, but something has to do it.
Load is applied at roof level. 3/4" plywood diaphragm. Would you feel comfortable just using a long piece of glulam blocking with a couple rows of 16d nails through the plywood into the top of the blocking to resist the load? I have up to 10' available for the length of the blocking. I have mono trusses framing perpendicular to the blocking... trusses are parallel to girt.
Any better ideas?
Load is applied at roof level. 3/4" plywood diaphragm. Would you feel comfortable just using a long piece of glulam blocking with a couple rows of 16d nails through the plywood into the top of the blocking to resist the load? I have up to 10' available for the length of the blocking. I have mono trusses framing perpendicular to the blocking... trusses are parallel to girt.
Any better ideas?






RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
BA
RE: Point load applied to roof diaphram
Again, a sketch would help.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Point load applied to roof diaphram
I was laughing so hard last night I couldn't sleep.
RE: Point load applied to roof diaphram
I am just concerned about putting that much of a point load into the wood diaphragm. There are openings in it for dormers about every 16' too to complicate things. Distance to wood shear wall from point load is about 16' horizontal.
RE: Point load applied to roof diaphram
If I understand what you are trying to do, I don't think I like it.
I need more info to give you any helpful advice. For wood framing the architect is really trying to do a lot here... You may need some steel.
RE: Point load applied to roof diaphram
HAHAHAHAHAHAHAHAHAHAHAHA
Unneutral ...Thank you. That was funny.
RE: Point load applied to roof diaphram
Can you put sway bracing in the lower mono trusses (in the plane perpendicular to your sketch)?
You should be able to transfer your load into the sway braing and back into the diaphragm.
RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
That was my original idea. It is a total pain because the state I'm in does expedited foundation/site plans for construction while the framing is being approved. Footings are already in. I don't have anything substantial enough below the truss to create a shear wall at the mono truss. I am hoping to get through this without a big change order.
Keeping it in the roof diaphragm is ideal. Your bracing idea in the monotrusses is something else I have considered and will likely include that too along with the strut.
a2mfk-
This is a gable end wall. There is no opening, just a half-@$$ed sketch. What isn't drawn is underneath the wind girt is a tall wood framed wall. An open stairwell is to the left side of the ridge. I posted about another tall wall a couple days ago, but this is a different situation. I haven't convinced myself that I like it either, that's why I'm questioning it. :)
RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
I'd say 100% that is the way to go.
Set your last truss inside the balloon framed wall.
RE: Point load applied to roof diaphram
I appreciate the help. Usually the simplest approach is the best, I've found.
RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
You'll need the fireblocking to prevent the fire from igniting the helium-filled ballons. The results could be catastrophic!
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Point load applied to roof diaphram
Thanks for the lesson on balloon framing though, Mike.
RE: Point load applied to roof diaphram
you poking fun at my terminology?
RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
Even though I use the same terms, I have fun wherever I can. After 40 years of this stuff, I need it. Thanks for the opportunity.
By the way, just checkin that you guys were reading my posts with the helium comment, OK? (just kidding)
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Point load applied to roof diaphram
No offense taken...I have been accused being a smart a$$ here and there too.
RE: Point load applied to roof diaphram
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
RE: Point load applied to roof diaphram
Also, if you are balloon framing the end wall, remember anchorage for suction on that wall. You may have to use some tension straps at the top of the framing to get the load into the roof...