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Maker of Fine Sawdust
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Discussion Starter · #1 ·
I was on another forum and this guy was saying that 5/8" drywall loses its 1 hour fire rating if it is put on a ceiling with 24" OC. Why would this be? Or is it not?
 

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Sag. Case of the droopy drywall. USG stuff only has drawings for approved 1 hr assemblies in wood frame on 16 OC, not 24.
 

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Maker of Fine Sawdust
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Discussion Starter · #3 ·
Now I'm just being curious.

What would be required to get a 1 hour fire rating using 5/8", 2 sheets thick?

I have heard of ceiling board which is stiffer and designed for 24 OC. Does it come in a 5/8" and would it have the fire rating?
 

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I always use 5/8s in all my ceiling repairs then coat tham with 1/8" Durabond 90 and the 1/8" topping, I wonder if this raises the rating.
 

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KemoSabe
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Now I'm just being curious.

What would be required to get a 1 hour fire rating using 5/8", 2 sheets thick?
We had the option of either double 5/8" X on 16" centers framing, or using metal track with one layer of 5/8" X. That was several years ago, things may have changed.:thumbsup:
 

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Pompass Ass
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We had the option of either double 5/8" X on 16" centers framing, or using metal track with one layer of 5/8" X. That was several years ago, things may have changed.:thumbsup:
How can you get a 1 hour rating with 1 layer of 5/8 type X, when you get 20 minutes for 1 layer of 5/8 type x, and 20 minutes for the stud?
 
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