2 Hour rated exterior wall

[tuzi]

I am looking for a UL design or GA for

1. 2-hour exterior wall
2. bearing wall
3. no batt insulation within the stud space
4. 2 layers of 5/8” Type X gypsum board on interior side
5. 1 layer of gypsum board on the exterior side

I searched on the UL website and GA. It seems like
1. if the batt insulation within the stud space is optional, then 2 layers of ¾” Type X gypsum board or 3 layers of ½” Type X gypsum board on the interior side are required
2. if 2 layers of 5/8" Type X gypsum board on the interior side, then batt insulation is always required (did not note as "optional" in UL design).

Anyone run into a similar situation? Thanks!

 

[Yikes]

To clarify:
Are you looking for wood studs, or metal studs?
If wood studs, fire-treated or not fire treated?
What is the exterior finish that is being applied over the gyp board?

 

[tuzi]

Sorry, missed some information. Steel stud framing, exterior finishes are fiber cement siding or thin brick.

 

[steveray]

soooooo....where are you getting your insulation?

 

[tuzi]

Ci only on the exterior.

 

[Tim Mailloux]

Ci only on the exterior.

is your concern with adding insulation in the stud cavity dew point / condensation related?

 

[tuzi]

Yes. From the dew point analysis, we don't want batt insulation within the stud.

 

[Tim Mailloux]

Yes. From the dew point analysis, we don't want batt insulation within the stud.

INTELLO PLUS - pro clima international

Reinforced hydrosafe® high-performance vapour check, suitable for all fibrous insulation materials

proclima.com

I have used this product on a few recent projects, is a Smart Vapor retarder that changes permeability with the seasons and allows for outward or inward drying of the stud cavity. If you opt to got his route you would need to spec a vapor permeable Air & Water Barrier.