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Gyp Board Shear Walls for Multi Story Apartment Building 2

AlexH15

Structural
Nov 14, 2012
13
I'm designing a 4 story apartment complex (wood framed). It is quite long and narrow. The layout is townhouse style so there are full width party walls that can provide a lot of shear capacity. I would like to use gyp board for the shear walls and it works from a load standpoint. My concern is during construction - the contractor wont be able to install the gyp until the roof is installed. This means there will only be temporary bracing on the lower floors while upper floors are being installed. Does this mean that I can't use gyp on the lower floors? I'm currently calling out for temporary bracing at all floors until the sheathing can be installed, but I'm worried that might not be enough. Any thoughts?
 
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I think if you put the onus on the contractor to brace the structure during construction, you are covered. Specifically mention that in specs, general notes on drawings, etc.
 
If you are the structural engineer of record and you are working for a contractor on a Design-Build basis, then looking into the phases of construction and temporary bracing might be your responsibility. You should be concerned as to how the framing is laterally braced against drifting prior to the shear wall sheathing installation.

However, if you are working for an client directly, or through an Architect, you should be careful on inserting yourself into the "means and methods" of bracing during construction. Speaking for my own firm, we avoid telling the contractor how to build and how to brace as our insurance doesn't cover that. It's the contractor's responsibility.
 
I'm designing a 4 story apartment complex (wood framed). It is quite long and narrow. The layout is townhouse style so there are full width party walls that can provide a lot of shear capacity. I would like to use gyp board for the shear walls and it works from a load standpoint. My concern is during construction - the contractor wont be able to install the gyp until the roof is installed. This means there will only be temporary bracing on the lower floors while upper floors are being installed. Does this mean that I can't use gyp on the lower floors? I'm currently calling out for temporary bracing at all floors until the sheathing can be installed, but I'm worried that might not be enough. Any thoughts?

Ugh. I personally hate the idea of relying on Gyp board for lateral resistance. The only time I've seen this done is when someone had an existing structure and they wanted to justify why should be allowed to do a renovation even though the lateral system didn't calc out.... Heck, I believe the example I'm thinking of used a FEMA / NEHRP provision at the time. Something that would now be in ASCE 31 / 41 now.
 
If you are the structural engineer of record and you are working for a contractor on a Design-Build basis, then looking into the phases of construction and temporary bracing might be your responsibility. You should be concerned as to how the framing is laterally braced against drifting prior to the shear wall sheathing installation.

However, if you are working for an client directly, or through an Architect, you should be careful on inserting yourself into the "means and methods" of bracing during construction. Speaking for my own firm, we avoid telling the contractor how to build and how to brace as our insurance doesn't cover that. It's the contractor's responsibility.
Thanks for the response! I am the consulting engineer so construction is not in my scope. I have various notes saying to brace adequately and hire an engineer to design it if necessary.
 
Ugh. I personally hate the idea of relying on Gyp board for lateral resistance. The only time I've seen this done is when someone had an existing structure and they wanted to justify why should be allowed to do a renovation even though the lateral system didn't calc out.... Heck, I believe the example I'm thinking of used a FEMA / NEHRP provision at the time. Something that would now be in ASCE 31 / 41 now.
It's not my go to either but it saves 10's of thousands of dollars of materials and makes wall finishing much less complicated. The shear utilization is absolutely tiny since the walls are super long and spaced pretty tightly.
 
If you are the structural engineer of record and you are working for a contractor on a Design-Build basis, then looking into the phases of construction and temporary bracing might be your responsibility. You should be concerned as to how the framing is laterally braced against drifting prior to the shear wall sheathing installation.

However, if you are working for a client directly, or through an Architect, you should be careful on inserting yourself into the "means and methods" of bracing during construction. Speaking for my own firm, we avoid telling the contractor how to build and how to brace as our insurance doesn't cover that. It's the contractor's responsibility.
ASCE 37 already explicitly points at the contractor for bracing the construction. Whether it’s “written down somewhere in the contract documents” or not, the standard of care is that the builder is responsible for making sure that it doesn’t fall down while he/she builds it.
 
Side question - are there specific nailing requirements to use gyp as a lateral system - similar to plywood walls? Just out of curiosity - never left California so it's not in my wheelhouse
 
Side question - are there specific nailing requirements to use gyp as a lateral system - similar to plywood walls? Just out of curiosity - never left California so it's not in my wheelhouse
Table 4.3C, from SDPWS 4.3.7.5.
 
ASCE 37 already explicitly points at the contractor for bracing the construction. Whether it’s “written down somewhere in the contract documents” or not, the standard of care is that the builder is responsible for making sure that it doesn’t fall down while he/she builds it.
But if the project is Design/Build and the EOR works directly for the contractor then it "may be" that the engineer is sucked in to deal with temporary construction loads and stability during erection. Depends on the D/B contract of course but it does happen.
 
I wonder is sheetrock fastening is part of the AHJ inspection process? Usually it goes from rough-in to final.
 
I wonder is sheetrock fastening is part of the AHJ inspection process? Usually it goes from rough-in to final.
Around here, it's part of the sheathing inspection if they notice that it's on the shear wall schedule.

Might be worth making it a special inspection.
 

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