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U-336 and stand alone in townhouse

jar546

jar546

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We have a permit to build 4 townhouses under the 2006 I-codes (don't ask).

Anyway, the architect who did not stamp nor does he need to stamp the residential plans as specified UL U-336 as the 2 hour separation between houses.

In the attic, his is only showing the 2 layers of 1" gypsum board with no other supporting frame or structure and he is claiming that as long as you maintain the minimum 3/4" airgap between adjacent framing, it is OK.

I cannot see any part of U-336 that would allow just the 2 layers of 1" gypsum as a stand alone even though it is in the attic area. Has anyone ever come across this set up before.

I am flagging it as incorrect for more than one reason but want to check with everyone on this. thanks

jeff
 
In our townhouses they attach the clips to the roof trusses for support. I expect to see the metal track and H-studs all the way to the bottom of the FRT roof deck.

I happen to think this is a great separation assembly.
 
Same as what you are looking at --- and TJ has the right answer.

In the old days, the first 20 or 30 pages had limitations for the designs and stated some important information that may be revelent to this conversation - Does anybody know how to find the opening pages of the UL directory?
 
Spoke with UL today. There was never any testing done with the two 1" panel only. The testing was always done with an assembly that included the associated framing for support.

UL seems to think that this wont be a problem as long as the clips are properly placed. I will let it fly since it is a common wall.

Thanks
 
so am I understanding this right two layers of one inch sheetrock with H channels, air gap, and that is it??
 
cda said:
so am I understanding this right two layers of one inch sheetrock with H channels, air gap, and that is it??
Click to expand...
You got it. The infinite airgap is OK. All you need is 2 layers of 1" sandwiched together with he H channel
 
I guess I am missing something on the ul listing???

7. Non-Bearing Wall Partition Intersection — (Optional) Two nominal 2 by 4 in. stud or nominal 2 by 6 in. stud nailed together with two 3in. long 10d nails spaced a max. 16 in. OC. vertically and fastened to one side of the minimum 2 by 4 in. stud with 3 in. long 10d nails spaced a max 16 in. OC. vertically. Intersection between partition wood studs to be flush with the 2 by 4 in. studs. The wall partition wood studs are to be framed with a second 2 by 4 in. wood stud fastened with 3 in. long 10d nails spaced a max. 16 in. OC. vertically. Maximum one non-bearing wall partition intersection per stud cavity. Non-bearing wall partition stud depth shall be at a minimum equal to the depth of the wall.
 

Go to page 14 for a look at a typical installation drawing The fire test design was U366 that JAR I belive was looking for.



Fire Test: UL R1319, 89NK28786,

5-14-90, UL Design U336;

UL R1319, 94NK40690,

1-27-95, UL Design V411;

​
WHI 495-PSV-1245, 4-28-83




AREA SEPARATION FIRE WALLS

(PARTY/FIRE WALLS)

Fire-resistance rated gypsum board systems (solid

and cavity types) can serve as area separation fire walls

(also known as party walls or fire walls) between

adjacent wood frame and steel frame dwelling units

such as townhouses, condominiums, and apartments;

and in commercial and institutional buildings. These

walls are erected one floor at a time, beginning at the

foundation and continuing up to or through the roof. At

intermediate floors metal floor/ceiling track shall be

installed back-to-back to secure the top of the lower

section of the partition to the bottom of the next section

being installed.

At intermediate floors and other specified locations

the area separation fire walls shall be attached to

adjacent wood or steel framing on each side with

aluminum clips that soften when exposed to fire (Figure

3). If one side of the structure becomes involved in a

fire, the clips on the fire side allow collapse of the

structure on that side. The clips on the other side

support the area separation fire wall keeping it in place,

thereby protecting the adjacent structure. Consult

gypsum board manufacturer for clip detail, placement,

and height limitations. Openings and through

penetrations, including protected openings and

penetrations, are not permitted in the area separation

fire walls contained in this manual.

​
 
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