Drywall question

[KubotaSteve]

I'm getting ready to add a mudroom and garage to my house. In the rules and regs. I got from the county they state that the garage has to have 1 hour fire resistant drywall on the wall connecting to the mudroom. I've never seen or heard of fire resistant drywall. Are they talking about a standard drywall that will resist fire for that long? If so what thickness would that be?
Our county has implemented new codes recently so I just want to make sure I get everything right.

 

[CharlieTR]

I am not positive but I think that means it must be 5/8" thick on that wall.
The other walls can be thinner, like 1/2", but most people use 5/8" anyway.

 

[BillBee]

Fire Resistance drywall is 5/8s and will be stamped Fire Resistance. Up here in the Northeast it’s about $7.25 a sheet and heavy to handle. Although no building codes in the town of VT that I am building in, I’m using 5/8s in the garage under, boiler room and main level, with the exception of ½ in on the 18ft cathedral ceilings. Drywall also comes in ½ in. and 3/8s (3/8s is flimsy) but is not categorized as Fire Resistance. I’m not familiar with ¼ in.

 

[mjarrels]

There is also a paperless drywall available... no mildew problems.

mark

 

[RobertN]

5/8's. And, the entire wall of the garage must be completely taped and sealed, even if it is an unfinished garage. California has been like that for a long time.

As mentioned, it can be heavy, especially in 12' sheets.

 

[KubotaSteve]

Thanks for the help fellas.
I understand the reasons for these codes, but they can be a pain!!!!

 

[CurlyDave]

I can handle 1/2" 4'x8' sheets easily by myself. Especially if I use a "kicker" to lift onto the wall. 5/8" is a strain, but doable, if they are not going on the ceiling.

I would definitely need a helper to handle 4' x 12' sheets of either thickness, and the 5/8 would be no fun at all.

I am an official geezer (62), but in pretty good shape for that age.

 

[_RaT_]

I can handle 1/2" 4'x8' sheets easily by myself. Especially if I use a "kicker" to lift onto the wall. 5/8" is a strain, but doable, if they are not going on the ceiling.

I would definitely need a helper to handle 4' x 12' sheets of either thickness, and the 5/8 would be no fun at all.

I am an official geezer (62), but in pretty good shape for that age.

A drywall lift is the only way to go. 5/8" X 12' Type X for 1 hour fire rating is a piece of cake to hang on the ceiling. The hardest part is getting it on the lift if by yourself.

 

[NY_Yankees_Fan]

Check out this web site for design. The type of board, MUST BE TYPE X, and the nail pattern is very important.

Design Code For Acceptance 3 - Fire Rated Wood Floor and Wall Assemblies

See bottom of the page for designs as below.

2 x 6 wall

. Framing - Nominal 2x6 wood studs, spaced 16 in. o.c., double top plates, single bottom plate
2. Sheathing - 5/8 in. Type X gypsum wallboard, 4 ft. wide, applied horizontally, unblocked. Horizontal application of wallboard represents the direction of least fire resistance as opposed to vertical application.
3. Fasteners - 2-1/4 in. Type S drywall screws, spaced 7 in. o.c.
4. Joints and Fastener Heads - Wallboard joints covered with paper tape and joint compound, fastener heads covered with joint compound

2x4 wall

1. Framing - Nominal 2x4 wood studs, spaced 16 in. o.c., double top plates, single bottom plate
2. Sheathing - 5/8 in. Type X gypsum wallboard, 4 ft. wide, applied horizontally, unblocked. Horizontal application of wallboard represents the direction of least fire resistance as opposed to vertical application.
3. Insulation - 3-1/2 in. thick mineral wool insulation (2.5 pcf, nominal)
4. Fasteners - 2-1/4 in. Type S drywall screws, spaced 12 in. o.c.
5. Joints and Fastener Heads - Wallboard joints covered with paper tape and joint compound, fastener heads covered with joint compound