Metal Stud Bracing - Brick cavity wall
Metal Stud Bracing - Brick cavity wall
(OP)
For a brick/metal stud cavity wall (veneer brick - 1" airspace - 2" rigid insulation - (exterior sheathing?) - metal stud - interior gyp.) curtain wall style construction.
Is it common practice anywhere to allow the architect to omit the exterior sheathing layer at the exterior face of stud and attach the rigid insulation directly to metal studs (provided brick ties are attached directly to metal studs)?
In the past I have required the exterior sheathing layer (densglass or similar) and attached brick ties either to or through that layer to metal studs beyond. I consider the studs to be braced continuously for this case and all wind loads transfer to the studs. I am currently working for a new client who wants to attach the rigid insulation directly to the face of stud. They have justified the waterproofing on their end.
What are the general thoughts about relying on the brick ties (acting through 2" insulation and airspace)/brick or rigid insulation itself to brace the exterior face of metal stud?
It also seems odd to me to not have a span-rated component other than the brick as part of the wall envelope. If the brick ties do not hold up and some brick fails (which I have seen happen from time to time) we have weather blowing directly into the building. On the other hand I guess this is not much different than many metal panel systems that attach directly to framing. This is just not standard construction for me and I am a little hesitant. Any literature available on the topic?
Is it common practice anywhere to allow the architect to omit the exterior sheathing layer at the exterior face of stud and attach the rigid insulation directly to metal studs (provided brick ties are attached directly to metal studs)?
In the past I have required the exterior sheathing layer (densglass or similar) and attached brick ties either to or through that layer to metal studs beyond. I consider the studs to be braced continuously for this case and all wind loads transfer to the studs. I am currently working for a new client who wants to attach the rigid insulation directly to the face of stud. They have justified the waterproofing on their end.
What are the general thoughts about relying on the brick ties (acting through 2" insulation and airspace)/brick or rigid insulation itself to brace the exterior face of metal stud?
It also seems odd to me to not have a span-rated component other than the brick as part of the wall envelope. If the brick ties do not hold up and some brick fails (which I have seen happen from time to time) we have weather blowing directly into the building. On the other hand I guess this is not much different than many metal panel systems that attach directly to framing. This is just not standard construction for me and I am a little hesitant. Any literature available on the topic?






RE: Metal Stud Bracing - Brick cavity wall
At a minimum, strap braces and bridging.
RE: Metal Stud Bracing - Brick cavity wall
RE: Metal Stud Bracing - Brick cavity wall
RE: Metal Stud Bracing - Brick cavity wall
I feel that the interior and exterior sheathing provide the majority of bracing for metal stud wall and counting on the bridging is sketchy at best but I guess it is something we have to trust. Using a block and strap detail and then adding diagonal straps to that is a better, yet costlier system.
Between this new Dow system, the new anchoring limitations, crappy BIM drawings and inattentive and unreasonable EOR's I think I am going to quit the metal stud business.
RE: Metal Stud Bracing - Brick cavity wall
Dik
RE: Metal Stud Bracing - Brick cavity wall
I guess you could justify the use AISI C3.1.3 (Beams Having One Flange Through-Fastened to Deck or Sheathing) provisions and reduce the moment capacity accordingly, but that is relying on the interior gyp alot more than I am comfortable with - and you end up with a 50-65% reduction in moment strength. - I assume something like this is what you are referring to XR250
RE: Metal Stud Bracing - Brick cavity wall
I think the solution is to require that they add the layer of gyp sheathing on the exterior below the foam.
This is why I dislike these jobs. By the time they hit my desk, I have no say in the matter and the owners are always trying to cut costs so convincing them to add a layer of gyp is futile.
RE: Metal Stud Bracing - Brick cavity wall
RE: Metal Stud Bracing - Brick cavity wall
RE: Metal Stud Bracing - Brick cavity wall
RE: Metal Stud Bracing - Brick cavity wall
RE: Metal Stud Bracing - Brick cavity wall
They state that it only acts to brace the stud when it less than I believe 8" inches in depth. I have always counted on this to brace my stud in my design and not required sheathing on the exterior face; no complaints yet from contractors on the price.
RE: Metal Stud Bracing - Brick cavity wall
Also you can bring up the current energy code being based on assemblies that may require dens, you have Air barrier requirements for buildings, you have NFPA 270/258 (? the bad one, whatever that number is) that only has testing on assemblies...
RE: Metal Stud Bracing - Brick cavity wall