“Fire-wall” attic of attached garage?
PatchogPhil
| Posted in Construction Techniques on
What construction makes a fire-wall rating for the wall separating the attics above an attached garage and the rest of the house?
Situation is an attached garage. The garage ridge is inline with house ridge, but lower in height. The attic of the garage is separated from the attic of the house and cathedral livingroom with a 2×4 partition wall.
What materials are alowed on that garage attic partition wall to be fire-rated? I know 5/8″ fire rated drywall is one. Is any type of wood sheathing allowed? Which side?
Walk Good
Replies
You should check your local code. Generally though, a layer of 5/8 Type X drywall on each side, taped and coated, with no through penetrations.
Arguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.
I'm with Andy.
While anything may be better than nothing in the way of a "firestop", whatever your local building department wants is what you need to be finding out.
Room service? Send up a larger room.
I agree that the local code officials have final say.
What I am asking is what construction method BESIDES 5/8" drywall is GENERALLY considered a fire-stop in this situation.
I don't know of any, but, if you've got the drywall in place, it may be permissable to put wood over it.Arguing with a Breaktimer is like mud-wrestling a pig -- Sooner or later you find out the pig loves it.
I've only seen 2 things used for firestops - Firecode drywall and masonry. (brick or block)
I have occasionally seen 3/8 plywood used as a DRAFTstop. But that's something else altogether.Here's to our wives and girlfriends may they never meet!
if memory serves me correct, 3-5 inches of concrete is a fire wall. there are exterior rated gypsum panels that are X rated and some interior gyp core panels that can be left exposed up to 12 months. So many inches of mud per hour.
Commercial fire code is a whole other ball game from 1-2 family residential.
Edited 2/27/2004 7:40:45 AM ET by WmP
There are many different types of fire rated walls. Heck, even a wood stud, unprotected wall has a fire rating (0). Tell me how long you are looking to get and I'll tell you what wall detail you'll need.
Last I saw it be an issue (about 6 years ago), around here they wanted one layer of firesheld drywall, taped.
But the inspector is the guy to ask.
What you need is a descriptive list of fire rated assemblies. There was one in the last office I worked in... trying to remember what it was... possibly a softbound edition of the UBC that we kept around. You could doubtless locate a good reference by contacting the Builder's Booksource, in Berkeley, California. No doubt they have a website. You do not have to support The Governator to shop there.
Bingo!
Just looking for examples of "fire rated assemblies" besides 5/8 drywall, masonry or masonry-related.
Thanks!
Walk Good
Phil
Well, I have the book that was mentioned in the above post. There are several THOUSAND different possibilites.
patch... first lemme say.. missed you around here.. are you comming to RhodeFest in August ?
2d..
most old codes required 1hr. seperation... in the One & Two Family Dwelling code.. but..
in reality that was extremely difficult to really comply with ..
as far as i know.. ( and you should check with your local code enforcer).. the only seperation required now is 20 minutes..
regular steel doors.. and 1/2" gypsum will cover that..
if your question is how to BEST get fire seperation... then just imagine (or draw ) all of the sections bewteen your garage and the living spaces.. then figure out how to modify them to suit your desires...note that any penetration will be the usual weak link.. so concentrate on thoseMike Smith Rhode Island : Design / Build / Repair / Restore
Hi Mike
I've missed "being" here. Glad someone noticed! :-)
The reason I've asked about this issue is I've got a repair to do at M.I.L. house. Seems her 18 month old hydronic boiler (in room within garage) decided it wanted to be a steam generator ( pressure reducer valve died and the T&P valve spewed steam for probably a week at over 100 PSI full water main pressure). Steam went up and condensed on underside of the cold roof in garage attic. Which then dripped down onto drywall ceiling of garage, which then fell off in sections. I went looking for broken pipes or leaky roof, there was so much water. Then I heard the ppssssttttt from the boiler room.
So old drywall has to come off (whatever remains). Either new drywall goes up, or comply with code issues for fire blockage from garage. Wanted to know different types to pick from.
Seems that new 5/8" drywall on ceiling would be easiest to do anyway.
Walk Good
Phil
Uh oh. Someone didn't pipe their t&p valves to the exterior per code. If she wants to sue the radiant guy he's a sitting duck.
From what I understand, around here, the T&P valve is piped to hover over a floor drain.
Thus allowing the steam to rise.
Last boiler I installed the inspector wanted the t&p piped to the exterior, not more than 6" above grade, pointing down, 100% hard-drawn copper pipe, slope 1/8 per foot or more. He said that before he even got out of his truck. Your story is the best I've ever heard about why it shouldn't be anywhere inside, drain or not.
In my googling I often run into odd sites.
A few days ago I found one one realestate, but it had a column by a home inspector.
It seems that this is a HUGE topic amoung code inspectors and home inspectors.
It appears to be on par with the vent wars.
Some thing that it is best outside to limit extranous damage.
Other feel that is should be internal so that one knows when it is letting off (or leaking).
And a number of them do leak. I could well see one exiting to the outside in a cold climate that either leaks or lets off a little from time to time freezing up and blocking the line.
All of the discussion that I read had to do with WH's.
Ok, there are a number of different systems you can use. I'm going to limit this to drywall and wood studs. Now, this is going to give you a rated wall assembly. This is not a firewall. Firewalls typically are rated for 3 or 4 hours and extend above the roof structure. A bit of overkill here.
Design U305 Bearing wall rating: 1hr. Finish Rating: 20-26 min.
Nailheads: Exposed or covered with joint finisher
Joints: Exposed or covered w/fiber tape and joint compound, except where required for specific edge configuration. For tapered, rounded-edge wallboard, joints covered w/joint compound or fiber tape and joint compound. As an alternate, nom 3/32" thick gypsum veneer plaster may be applied to the entire surface of Classified veneer baseboards. Joints reinforced.
Wallboard, Gypsum (UL rated): 5/8" thick wallboard paper or vinyl surfaced, with beveled, square or tapered edges, applied either horizontally or vertically. Wallboard nailed 7" oc w/6d cement coated nails 1-7/8" long, .0915" shank diam and 1/4" diam heads. When used in widths of other than 48", wall board is to be installed horizontally. Wall board shall be: James Hardies Gypsum-Types Fire X, Types III or IV, Types V, VI, VII, Vi-WG, VI-ISH or Unites States Gypsum Co.- Types AR, SCX, C, WRX, WRC, 1p-X1, FCV, IP-X2, SHX (there are more mfr's here than what I listed)
Studs: 2x4's 16" oc and firestopped
Insulation: (optional) glass fiber or mineral wool insulation placed in stud cavities.
Design U306 Bearing wall rating: 1hr. Finish Rating: 20 min.
Nailheads: Exposed or covered with joint finisher
Joints of exposed boards: Exposed or covered w/fiber tape and joint finisher
Wallboard, Gypsum (UL rated): 3/8" thick gypsum wall board applied in two layers, the first layer of boards placed vertically and temporarily nailed in position, the second layer coated w/glue, applied against the first layer and nailed to studs 6" oc at edges of boards and 8" oc at intermediate studs w/1-7/8" 6d, cement coated nails. Wall board shall be: Boral Gypsum Inc.-type "DDG2" or G-P Gypsum Corp.-type "GPFS1"
Studs: 2x4's 16" oc and firestopped
Design U307 Bearing wall rating: 1hr. Finish rating: 25 min.
Wallboard, Gypsum (UL rated): 1/2" thick wallboard fastened w/5d cement coated nails 1-5/8" long, .086" shank diam. and 15/64" in diam heads spaced 7" oc and installed horizontally. As an option, nom 3/32" thick gypsum veneer plaster may be applied to the entire surface of the calssified veneer baseboard. Joints reinforced. Wall board shall be: Boral Gypsum Inc.-types BG-C, DDDG3, DDG2 or James Hardie Gypsum-types III or United States Gypsum Co.-Types RG-1, RG-3, RG-C (there are more mfr's here than what I listed)
Wood particle board: 7/16" thick 4' wide. Wood particle board installed vertically and fastened w/6d, 2" long, finishing nails space 7" oc and staggered from nails of wallboard (or lath). Nail heads filled w/matching putty filler.
studs: 2x4's 16" oc and firestopped
Insulation(UL listed): (optional) mineral wool insulation placed in stud cavities.
Design U309 Bearing wall rating: 1hr Finish Rating: 27 min.
Wallboard, Gypsum (UL rated): 5/8" thick, 4' wide nailed to studs and bearing plates w/6d cement coated nails 1-7/8" long, 0915" shank diam and 1/4" diam heads spaced 7" oc. Wall board shall be: Boral Gypsum INc.-type GB-C, DDN1 or G-P Gypsum Corp.-Types 5,9, DGG, GPFS6, GPFS-C (there are more mfr's here than what I listed)
Joints and nail head: wall board joints covered w/paper tape and joint compound. Nailheads covered w/joint compound. Gypsum plaster not more than 1/8" thick may be applied over teh wall board in addition to the specified joint treatment.
Batts and blankets(UL listed): Optional glass fiber insulation
studs: 2x4's 24" oc and firestopped
Ok, that's enough typing for now. These systems should cover most installations. I havn't even gotten to the 2x6's yet. There are still several pages of 2x4 installations (I posted about a page and a half). Now, there are whole lists of mfr's who's products are approved for the installation. I just didn't feel like listing all of them. No, you cannot substitute materials. If a item is specified, it must match the spec exactly or the rating is void. If it's not listed, then it doesn't matter. Now this in only a 1 hour rated wall. If you read the above closely, you'll notice that this is the typical interior residental installation. Now, I recall the garage-house walls have two layers of drywall on them. These might be a 2 hr rated wall. I'm going to save that for another post though.
Edited 2/27/2004 10:05:10 AM ET by Tim
Thanks for the info Tim.
Walk Good
Phil
Finally got to the library and looked at the code books for here. My township adopts NY State building code. The version "in force" states for the attached garage wall shared with living space requires "a 3/4 hour fire rating ... or 5/8" fire rated gypsum on garage side with 1/2" regular on living side".
Ceiling calls for 5/8" fire rated gypsum.
All existing original ( circa 1970) drywall in this garage is regular 1/2". I guess the building codes didnt require anything more or the inspector didnt notice if different.
The existing drywall on wall separating the garage from living area isn't damaged, just water stained. Seems that I can comply with the 3/4 hour requirement by layering another 1/2" regular drywall. Slightly lower cost and I can do it in 12' sheets in 1/2" vs 8' in 5/8". Since HD and Lowes, hardly any lumber yards around here and no one stocks 5/8" in longer than 8'. Would have to pay bigtime in delivery fees.
Phil
Edited 3/3/2004 4:46:20 PM ET by Patchogue Phil
Edited 3/3/2004 4:52:06 PM ET by Patchogue Phil