SDPWS Gypsum Wallboard vs. Gypsum Sheathing Board

[abusementpark]

Can anyone clarify the difference between gypsum wallbaord and gypsum sheathing board as indicated in Table 4.3C of the 2015 SDPWS for wood-frame shear walls?

It is not clear to me why these are two separate categories. The descriptions on page 33 indicate the material is per ASTM 1396 for both. However, for installation, gypsum wallboard references ASTM C 840 (Standard Specification for Application and Finishing of Gypsum Board) and gypsum sheathing board references ASTM C 1280 (Standard Specification for Application of Exterior Gypsum Panel Products for Use as Sheathing). I am not really sure what about the installation differs, since Table 4.3C covers the fastener type, fastening pattern, blocked vs. unblocked, stud spacing, etc.

Can I use gypsum sheathing board for interior shear walls even though the installation method for exterior?

 

[Aesur]

I believe the difference is that gyp wallboard is interior use only whereas the gyp sheathing can be used on the exterior.

[URL unfurl="true"]https://gypsum.org/commercial-applications/exterior-gypsum-sheathing/[/url]

 

[STrctPono]

Not sure if you are asking what the basic difference is or if this is more of a semantics question about the nuanced differences in the installation procedures per respective ASTM.

Gypsum wallboard is interior board like sheetrock.

Gypsum sheathing board is exterior sheathing like densglass.

SDPWS does give different values between the 2. The fastener type and spacing give the greatest variation in results.

I've never seen exterior sheathing like densglass put on the interior walls of a house.

 

[abusementpark]

Gypsum wallboard is interior board like sheetrock.

Gypsum sheathing board is exterior sheathing like densglass.

SDPWS does give different values between the 2. The fastener type and spacing give the greatest variation in results.

I've never seen exterior sheathing like densglass put on the interior walls of a house.

From a strictly material standpoint, SDPWS indicates both wallboard and sheathing board have to meet ASTM C 1396, but different ASTM installation methods. But Table 4.3 gives all of the critical installation requirements, so why two separate categories if the material spec is the same?

Here's the more exact question: Table 4.3C of SDPWS gives you an option to get 400 plf of nominal capacity with 5/8" sheathing board using a 4/7 pattern, 6d nails, 16" stud spacing, and blocked construction. Is there any reason I can't get the same capacity using wallboard, assuming all those requirements are met? Because the table doesn't give the same option for the wallboard and I am not sure what else about the installation would be different.

 

[EdStainless]

Have you read C1396?
There are 8 different categories of material covered by this spec.
Not all are the same.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy

 

[abusementpark]

Ah ok, that explains it then. Thanks!