Sheathing question

[William J. Decker]

In Chicago, houses that are within 8' of one another, laterally, and are frame with siding are required to have fire rated sheathing drywall. Does anyone know what stamps or type of drywall are required. I understand that, for awhile, the city required a fire rated drywall, but not one that was water resistant. Have a house where the clinet had their vinyl siding replaced (hail damage), and when the old stuff was removed, the house wrap and drywall had a lot of holes and was of many different types.

Anyone know the national requirements.

[Greg W. Mathias, CCHI]

Not sure about Chicago codes but I know that here it needs to be a single layer of 5/8 type X fire exterior rated drywall. It is hard to tell the type when on the wall as there is no stamp to go by. The grayish color is generally the exterior rated as shown in the first picture. the bottom portion does not look right to be exterior grade. Holes and penetrations are not allowed unless caulked with a fire rated caulking( usually red in color). The seams should also be fire taped. There is a new pink fire tape they are using now on joints instead of mud and tape. Hope this helps.

[William J. Decker]

Thanks, Greg. It does. I was clear on the generalities, but shy on the details. BTW: This was a City funded development. Kinda tells you how well codie around here do, don't it?

[Christopher Currins]

Red label, type X = Fire rated.

[Greg W. Mathias, CCHI]

A good way to tell if it is exterior grade is by feel. It should feel slightly waxy

[Greg W. Mathias, CCHI]

Yup, missed the X when I looked at the pictures.

[William J. Decker]

Looks like they used staples to secure it. No firestopping or taping. Typical crap Chicago work.

[Marcel R. Cyr]

Used that product many times on Commercial Buildings such as schools in the 70's and 80's, but sure was installed better than that.

Typically covered with #30 felt when used as a sheathing and no exposed edges exposed. Would fall apart with moisture when exposed.

http://www.americangypsum.com/products/detail/?p_id=137

[Larry D. Kage]

From Marcel's link:


Description


Exterior Gypsum Sheathing is a water-resistant product designed for attachment to exterior side-wall framing as an underlayment for various exterior siding materials such as wood, metal or vinyl siding, masonry veneer, stucco, shingles, etc. The panel is manufactured with a wax-treated, water-resistant core faced with water-repellent paper on both face and back surfaces and long edges.

Exterior Gypsum Sheathing is available in a 1/2" thick, 2' wide with a tongue and groove edge or, 1/2" & 5/8" thick, 4' wide square edge product. 5/8" Exterior Gypsum Sheathing has a Type X core, for use in fire rated assemblies.

Gypsum wallboard manufactured by American Gypsum contains no asbestos.
Basic Uses

Exterior Gypsum Sheathing is recommended for use in residential or commercial buildings, and provides fire resistance and additional structural strength when used under exterior finishes such as wood, metal or vinyl siding, masonry veneer, stucco, shingles, etc. Exterior Gypsum Sheathing is designed for direct attachment to wood framing with galvanized nails or staples and screws, or metal framing by the use of screws. The joints are not intended for finishing with drywall joint compound and tape.

[William J. Decker]

Larry, you are such a freakin' show-off.

Thanks;

[Marcel R. Cyr]

http://www.nationalgypsum.com/ng/res...pSheathing.pdf