Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Wind Girt Detail Feedback

Status
Not open for further replies.

XR250

Structural
Jan 30, 2013
5,409
This is a wind girt I am proposing for 27 ft. tall residential gable end wall. There are no easy opportunities to balloon frame it with 2x10's as it is cut to pieces with non-stacked windows. The LVL is 30 ft. long and spans from side wall to side wall. Would appreciate any feedback.
GIRT_djm6ty.png
 
Replies continue below

Recommended for you

30ft span for the LVL is quite long. How are you bracing the interior edge of the multi-ply LVL for negative wind pressures that push the wall from left to right in the photo? This will put the left side of the LVL into compression, and with an effective bracing interval of 30ft, you're bending capacity is going to be very low. May be able to try and justify the diagonal as a bracing method, but that would load a toenail connection in tension, which is not generally a good idea.
 
The 2x4s shown are 16" O.C. They are there to support the weak axis of the beam.
 
I suppose my thoughts are better shown below. What restrains the inside edge of the LVL from elastic buckling?

Capture.PNG7_rczlzm.png
 
I'd definitely use some sort of connector b/w that vertical and the LVL - A35 w/ 3 way bend seems appropriate.

Would be tempting to sheathe that vertical surface w/ plywood too but probably wouldn't do much with that aspect ratio.

 
Honestly, toenails in withdrawal hold decks to houses somewhat effectively but point taken. Strap or A35 seems like a plan.
Thanks for the feedback.
 
Instead of toenailing the verticals, you could build the vertical framing like a pony wall with continuous top and bottom plates, then attach the pony wall top plate directly to the LVL with screws or nails.
 
30" is a hell of a span. What is your detailing at the end?
Have you considered the combined deflection of the LVL beam + the supporting studs to make sure that the system is OK?

I would strongly look at using steel here, the performance is much more reliable

Also, I don't really understand the situation in which this is occurring...is there not a floor or ceiling you can use to take the out-of-plane loads?
 
Draw an elevation of the wall with openings, please.
 
1) Bad ass. I want to see pictures of the finished product.

2) For my own edification, how did you sell this to your architect? Nifty shelf for plants or something? Timeout seating for naughty children?
 
This is no better than anything else and may well be worse but I just can't resist a detailing challenge entry.

I'm sure that it would be sufficient to add the struts at 6' oc or whatever.

c01_wdsk78.jpg
 
KootK said:
For my own edification, how did you sell this to your architect? Nifty shelf for plants or something? Timeout seating for naughty children?

Yup, plant shelf. They have decided to add a wrap around porch so I may try to detail the roof as a deep beam in lieu of the plant shelf.
Would probably work just fine without detailing, however.
Thanks
 
Can I just suggest not doing this in wood? I.e. Steel.

XR250 said:
Honestly, toenails in withdrawal hold decks to houses somewhat effectively but point taken.

No, dude. Just no. They work just fine until somebody stands in the right place and the deck collapses and they die. You're forbidden from doing this in the code for a reason.

Edited to add image/code excerpt.
2018_IRC_R507.8_kjcha0.jpg
 
lexpatrie said:
Quote (XR250)
Honestly, toenails in withdrawal hold decks to houses somewhat effectively but point taken.

No, dude. Just no. They work just fine until somebody stands in the right place and the deck collapses and they die. You're forbidden from doing this in the code for a reason.

LOL, I was being a bit facetious. Honestly, I rarely call out deck connections unless it is a repair or the deck is tall or otherwise sketchy and then I specify the DTT1/2z's. We use the 2018 IRC - is it in there? If so it, is not enforced at all in my area and deck collapses are rare. 90% of the decks around here use toenails and ledgers. The rest use hangers which ain't much better for pull out. In the old days with screw or nail down PT pine decking, the last board would fasten to the band and help hold things in. Those days are gone with the hidden deck connection systems.
 
Wow. Just looked at it...hadn't realized that NC deleted the entire wood deck portion of the code to substitute in appendix M. They decided to completely ignore the improvements to deck design that keeps the deck from pulling away from the house. Fun. Now...they just say "bracing is required for lateral stability"...so if you don't have tension ties you would need it perpendicular to the wall, too...but I seriously doubt anyone is actually doing that.

It does call for a 2x2 ledger strip (let's not get started on that again) or joist hangers to support joists.
 
phamENG said:
Now...they just say "bracing is required for lateral stability"...so if you don't have tension ties you would need it perpendicular to the wall, t

...and we all know that the stiffness of the deck to house connection will trump the crappy knee-braced scenario so it will pull off the house before it engages anyway.
 
Gross. Deck failures are a real thing around here - Virginia Beach has instituted a strict 3 year inspection rule by an engineer for all short term rental properties. Not that it'll help - I've seen what one rubber stamp guy will "pass"...it's scary.
 
Makes sense. Seems like a lot of failures occur at the beach. Corroded fasteners, lot's of drunks and the sketchy decks held up by diagonal braces to allow easier parking.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor