# 5/8 inch drywall in garage?



## daxinarian (Jul 9, 2008)

what gets put into garages??? Gas Cans, and big gas cans on wheels with a heat source.
the prevelence of flamable materials like gasoline and combustion engines in garages make them a higher fire risk. Some areas are more stringent than others: In Houston, TX, the ceiling and all walls adjacent to living areas had to be fire rated. Here in Huntsville, AL, only the ceiling needs to be fire rated (or so I have heard).


----------



## skymaster (Jun 6, 2007)

NJ. ALL walls and ceilings fire rated 5/8" normal


----------



## Termite (Apr 13, 2008)

The international residential code requires all garage/house commonwalls and ceilings have an equivalent to a 20 minute fire membrane on the garage side. It allows 1/2" on the ceiling, unless the garage is beneath habitable rooms...If so, a 5/8" ceiling is required. Furthermore, it requires that all structural elements supporting the structure get the same treatment. That includes beams, steel beam posts, and stud walls. In most residential structures, nothing structural can be exposed in the garage. Garage/house doors must be 20 minute fire rated or 1-3/8" solid core, and any other openings must be equivalent (attic access hatches for instance). 

*5/8" sheetrock is not an IRC code requirement for walls under any circumstance in single family residential*. It is sometimes a jurisdictional requirement. It is often specified on plans though. 1/2" will get it done in many cases, with the one exception being habitable space above the garage. 

The reason for the pseudo-firewall requirement in garages is due to the high instance of garage fires. The rock serves the purpose of keeping fire and heat back for a short period of time to allow egress. For this reason, garages cannot ever serve as a means of egress and cannot open into sleeping areas. The rock protects the structure during a fire for a short period of time as well. 

Another thing that gets overlooked in garages is penetrations. PVC pipe penetrations of the fire membrane must be firestopped with intumescent firecaulk. All solid penetrations of the firewall must be firestopped with conventional firecaulk. No HVAC openings are permitted. Electrical penetrations (boxes, panels, etc) of the membrane cannot exceed 16 square inches...That is a 2-gang box. Anything larger is prohibited. I see electric panels in the garage commonwall all the time, and require them to be moved or enclosed in a 5 sided sheetrock enclosure with all penetrations firecaulked. Any electric boxes that meet the maximum 16 square inch requirement for a fire membrane must be rated boxes (2hr is common). Mudrings are not permitted because they allow easy passage of heat and fire.


----------



## Termite (Apr 13, 2008)

For the record, if it were my house I'd have 5/8" type X rock everywhere in the garage.

That extra 1/8" will buy several minutes of burn time. Sheetrock resists fire and heat passage for a short time simply by expelling its moisture content. When the rock is dried out completely by the fire, it is much less effective.


----------



## AtlanticWBConst. (May 12, 2006)

As KCT posted, it's required on the common walls/ceilings only. However, we always install it on all walls/surfaces, if the garage is connected. 

The cost difference from attempting to use 1/2" on the unrequired walls (to save money), is usually only about $10 to $20.00...so it's a no-brainer, in my book, to just use all 5/8" fire-rated...


----------



## buletbob (May 9, 2008)

thekctermite said:


> For the record, if it were my house I'd have 5/8" type X rock everywhere in the garage.
> 
> That extra 1/8" will buy several minutes of burn time. Sheetrock resists fire and heat passage for a short time simply by expelling its moisture content. When the rock is dried out completely by the fire, it is much less effective.


I agree :thumbsup:


----------



## 737Pilot (Mar 4, 2008)

My garage is a detached garage with no living quarters at all that's about 30' away from my house. Where would I be able to find the code for the drywall for this garage in Houston. Thanks.

I'm hoping to use all the extra 1/2 drywall that I have left over from the house. I'd hate to waste it.


----------



## buletbob (May 9, 2008)

737Pilot said:


> My garage is a detached garage with no living quarters at all that's about 30' away from my house. Where would I be able to find the code for the drywall for this garage in Houston. Thanks.
> 
> I'm hoping to use all the extra 1/2 drywall that I have left over from the house. I'd hate to waste it.


I not sure what your jurisdiction requires but here any garage that is detached from any living quarters you will be able to use 1/2".


----------



## skymaster (Jun 6, 2007)

Fat Albert driver: You should be able to use that 1/2 without a problem, for sure call ground for clearance but betcha ya cleared as filed. 
Storage > garage .
Jack:thumbup:


----------



## Termite (Apr 13, 2008)

Unless your detached garage is super-close to another residence, you can sheetrock it with anything you want. If it is very close to another house there will possibly be firewall requirements.

Man, I typed all that and it was detached! Urghhh! :laughing:


----------



## skymaster (Jun 6, 2007)

KC; Its OK its monday, a holiday and Gustav has clouded your mind.:yes::laughing:. Next is Hannah and that is on MY side of the country, we r gonna git sumting outta this one.


----------



## 737Pilot (Mar 4, 2008)

Thanks guys...sorry I didn't mention it was a detach. I didn't think of it until KC mentioned living quarters. The nearest house other than my own is atleast 800' away!


----------



## zmusashi (Nov 27, 2006)

Well I'm glad you typed all that, sir, it gave me some more information on rocking my attached garage here in CT. Never noticed the penetrations such as electrical box; my electrician just wired the basement/ attached wall and installed a four gang box with a mud ring... I will have to look into that!


----------

