phamENG
Structural
- Feb 6, 2015
- 7,314
This is a very narrowly focused question (I'm looking at you, XR250). I've encountered a "quirk" in the NC residential code I haven't dealt with before. I have a client who wants to use prescriptive braced walls - I'm okay with that since it usually results in fewer (or at least less severe) field errors when the framer says "what's a shear wall?" after the siding is on.
Here's the thing - North Carolina rewrote nearly the entire braced wall section. So where other states allow braced walls up to Vult=140mph, NC cuts it off at 130mph. BUT...there's an extra chapter at the end for High Wind areas with additional requirements for wall bracing. I'd call the AHJ for a discussion, but it's a federal holiday, so I figured I'd try my hand here first. Does anyone interpret that as meaning you can used braced walls (prescriptive) as long as you add on the additional requirements stated in Chapter 45? My guess is no, and if you're higher than 130mph you're required to provide engineered shear walls AND do the extra stuff in Chapter 45...that's fine, but I want to at least be aware of what other engineers are doing in the area.
I've already designed the shear walls, but finishing out the load path is proving a challenge and giving me a structure that looks unlike most houses in the area. So either I'm being over conservative or everyone else designing and building houses down here has little regard for the building code and requirements for engineering. Probably somewhere in between.
For reference, wall bracing is in R602.10 and the additional requirements for wall bracing in high wind areas is in R4506.2.
Thanks.
Here's the thing - North Carolina rewrote nearly the entire braced wall section. So where other states allow braced walls up to Vult=140mph, NC cuts it off at 130mph. BUT...there's an extra chapter at the end for High Wind areas with additional requirements for wall bracing. I'd call the AHJ for a discussion, but it's a federal holiday, so I figured I'd try my hand here first. Does anyone interpret that as meaning you can used braced walls (prescriptive) as long as you add on the additional requirements stated in Chapter 45? My guess is no, and if you're higher than 130mph you're required to provide engineered shear walls AND do the extra stuff in Chapter 45...that's fine, but I want to at least be aware of what other engineers are doing in the area.
I've already designed the shear walls, but finishing out the load path is proving a challenge and giving me a structure that looks unlike most houses in the area. So either I'm being over conservative or everyone else designing and building houses down here has little regard for the building code and requirements for engineering. Probably somewhere in between.
For reference, wall bracing is in R602.10 and the additional requirements for wall bracing in high wind areas is in R4506.2.
Thanks.
