AskCodeMan

Hello,

In a multi-family building, we are using UL # U341 as the party wall fire assembly to achieve our 1-hr separation. In past projects I have always specified 5/8" Type X gyp. board, one layer each side of the wall. The contractor is questioning the Type X designation of the board. When I re-look at the actual UL Assembly it doesn't specifically call out Type X.

Here's the UL Text:

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2. Gypsum Board* — 5/8 in. thick 4 ft wide. Gypsum board or lath applied horizontally or vertically, unless specified below, and nailed to studs and bearing plates 7 in. OC with 6d cement coated nails, 1-7/8 in. long, 0.0915 in. shank diam and 1/4 in. diam head. As an alternate, No. 6 bugle head drywall screws, 1-7/8 in. long, may be substituted for the 6d cement coated nails.
When Steel Framing Members* (Item 6) are used, wallboard attached to furring channels with 1 in. long Type S bugle-head steel screws spaced 12 in. OC.

When used in widths other than 48 in., gypsum board to be installed horizontally.  Any UL Classified Gypsum Board that is eligible for use in Design Nos. L501, G512 or U305. See Gypsum Board* (CKNX) category for names of Classified companies.

The note about UL classified g.b. doesn't apply to this actual assembly...

Help Please! Thank you.

Katrina

Ok, I'm going to be a dork and answer my own question...

Referencing the expanded UL options, there are a host of other UL approved boards (most of which are type x) but any of those types, 2 - 2H are acceptable.

Hope that the AHJ just doesn't automatically choose Type X when he's inspecting.

Katrina

I will respond further with additional information after I get back to my office, however, there are other destinations than the widely recognized "Type X" and the use of the term "Type X" is more generic than meaning one specific gypsum board type.

When using UL Designs for fire rated separations, keep in mind that each design is specific in its requirements, including (with possibly a few exceptions) that the same msnufacturer gypsum board be used on each side of the separation wall. Different manufacturer components may only be mixed if allowed in the design.

Go here: (place cursor over link, right click, select 'Open in new window') http://database.ul.com/cgi-bin/ulweb/LI ... izard.html

Click on 'Search for a Design that fits your needs' in the center of the page.
A 'Search Designs' menu opens, leave all options at their default settings, at 'Keyword Match' type in U341, then click 'Search'.

At "Search Results', click on the linked 'Fire-resistance Design No. U341 BXUV.U341.

Design U341 will open, scroll down to '2B. Gypsum Board*' through '2H. Gypsum Board*', there you will find the various manufacturers listed and the gypsum board they manufacture which is suitable for use for this design as the gypsum board listed as '2. Gypsum Board*'.

You will find Type X listed at most manufacturers, you will also find other options listed at some of the manufacturers. Most people generically think of all the options listed as 'Type X' even though there are options listed other than Type X.