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I've got 2 areas of drywall that I need to repair. One area is in the attached garage, where the walls are the inside, backing to the house. The second is an interior house wall.
I'm assuming because of code, the garage walls have fire proof drywall. Is it possible to tell just by looking at it?
Because I only want to buy one sheet, is there any reason (pros or cons)why I can't use the same drywall type (assuming it must be fire proof) in the house?
Thanks,
Mike
I believe all drywall is fire-resistant. You can call yr township to confirm. I had to add drywall blocking on the tops of open stud bays in my walls to satisfy the firecode.
Drywall by definition is fire proof.Quote:
Originally Posted by Mike Shields
usually code is more concerned with the quality of the taping, which will complete the fire proofing of the Drywall and also seal it from gases escaping into the home. exhaust fums from your auto are the biggest concern for your safety.
5/8 drywall is rated for a 2hr burn time. double up that 5/8's and you have 4hr's, if you tape both layers and stagger your seams.
You should ask your local building inspector. they are usually very willing to help with any information you might need and the service is free.
Keep in mind that anything built to code, is built to the minimum allowed by law. you can always do it better you just shouldn't do less.
Drywall comes in three varieties - standard, X and C. Standard 1/2" drywall has a 30minute fire resistance rating. 5/8" Type X with a denser core and fiberglass raises the rating to 1 hr. This is what is probably used on the garage wall, and costs about $.75 a sheet more than standard grade. Type X also dampens sound transmission.
Type C is even more expensive and is supposed to provide still better fire protection, but I have not found a listing of how much. I believe you can get an hour with 1/2" layer.
You may have issues patching the inside wall with 5/8" drywall if it was originally done with 1/2". Just buy two sheets if it was, it might be cheaper than doing the entire wall :D
Fire rated drywall is marked with an 'X' and is 5/8 inch thick in most cases. The paper on fire rated drywall contains a flame retardant that standard drywall does not have. Most building codes do require fire rated drywall between the house and an attached garage. Your local drywall supplier will point you to the appropriate drywall for your use.
Mike,
HD has small cuts of drywall in bins near where the sheets are stacked. Don't know if the pieces come in the 5/8" thick size but there is usually a bit of the 1/2" size.
Thom is probably right about the inside drywall being 1/2" and the garage side being 5/8". It can be a pain when trying to match a different size patch material. I ran into that in my kitchen. Some of the walls had 3/8" sheets and I didn't catch the size difference until I started taping 1/2" to 3/8". I didn't know that 3/8" drywall existed. I knew about 1/4" because I ran into that in the past.
Drywall is not fireproof. It is fire resistant.
The International Residential Code R309.2 Seperation Required for attached garages calls for "not less than 1/2" gypsym board".
No type of board is specified and taping joints is not specified. Typically if your joints are tight enough a building inspector would not make you"fire tape" a garage.
F.Y.I.
Depending on where you live the local fire marshall, can overide building code, and require a longer burn rating in a garage.