I’m in the process of building a rural cabin in an area that does not required building permits or inspections. However, I am interested in building to code.
I have a half loft in my cabin and I plan to apply 1x6TNG pine to the entire open vaulted ceiling.
Is it absolutely code required to drywall and fire tape the ceiling first? If not could somebody point me to the UBC or BOCA reference to this?
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Replies
i know of nothing in the One & Two Family Dwelling code that would require that. However... how are you going to insulate behind the T&G ?
You could put up 1/2" drywall & blow the cavity with cellulose Dens-pak.. then put up your T&G...better insulation & more pleasant working conditions.. better installation..
but really , your choice
Mike Smith Rhode Island : Design / Build / Repair / Restore
I agree with Mike . My question is how are you going to stop the air leaving via the cracks in the boards if you dont rock and tape it first ? It would be a poor building to heat or cool with out rock and insulation.
Tim Mooney
I plan on installing R38 Fiberglass batts in the rafters (2x12's) and 6mil visqueen vapor barrier. I know there won't be any airspace in the rafters, but it's steep (12/12) and has a standing seam steel roof so I'm not worried about snow and ice buildup.
I just have no interested in drywalling and taping 16' cathedral ceilings if I don't have to.
Thats going to be a hard job , but if it works , it sounds like a plan .
Tim Mooney
I did one just like that in '88. Works fine! Same owner still sending references.
If you've got the room, put two coats of clear poly on before installing. Sanding and dripping overhead is no fun.Excellence is its own reward!
I did a ceiling this way (without the drywall)two years ago. Works great, looks great and we're working in that home again right now. We vented a free air space above the insulation and used two coats of MagnaMax (catalyzed lacquer)for the finish. Since we had so many sq. ft. of wood to finish, the MagnaMax allowed a fast turnover rate in the shop. Finished all six sides equally.
Not a carpenter here but this is common wisdom from a friend who is a fireman. If the fire gets into the attic the house will likely be a total loss. Drywall, for all its faults, is a very good fire barrier when compared to other materials. The time it buys can let you get out and the firemen to get in. Just a thought.
Insulate with cellulose instead of FG and fire becomes much less of an issue.
Andy Engel, The Accidental Moderator
Good point Andy but to point out it is not because cellulouse is less flamable - it isn't - but because it stops drafting that can fan a flame. Excellence is its own reward!
Piffin, I think it's a bit of both. Cellulose is treated with fire retardants while FG is glass, and can't burn. However, the facings and binders in FG may be flammable. Toss some FG batting on a bonfire, then toss on a shovelful of cellulose. The difference is, um, enlightening.
Andy Engel, The Accidental Moderator
one of the pioneers in modern cellulose, Clem Williamson of RI Energy, used to demonstrate the imflammability of cellulose at home shows .....
by taking a fistful and putting a copper penney in the pile in his bare hand.. then heat the penney with a blowtorch until it glowed red...
if you tried that with fiberglass.....Mike Smith Rhode Island : Design / Build / Repair / Restore
Carry on guys but some cellulose will burn. Not with an open raging flame but still enough to cause trouble.
I rebuilt part of a house that experienced a cellulose burn. There was a metalasbestos chimney for a wood stove and six inch fibreglass in attic. The glass had been drawn well back from it when it was installed. Then a contractor was brought in to blow cellulose over it all. One specific Q he was asked was about the chimney. He said he always placed a metal shield around such before blowing to keep the fireproof cellulose off it.
Well, he lied. There was never any shield placed so he blew the stuff right against the metalasbestos chimney, even down into the fire ring collar spacer. The owner just happed to be going home for lunch, something he never does, when he saw smoke billowing out of the roof vents. He tore into it with a hose in one hand and the telephone in another. When he pulled the SR down off the cieling there were wads of red glowing cellulose, hot enough to burn holes in his sheet vinyl flooring underfoot.
On another job, I was hired on a crew to build a metal catwalk over the blown cells in a metal jail building attic so that maintainance workers could access the equipment. They told us that we didn't have to worry about fire from sparks since the cellulose was fire proof. We learned quick how wrong they were. Started working with spark blankets and water buckets and still missed some. The super got three midnight calls because of a spark turning into a hatfull of glowing ember after several hours.
The fiberglas will burn too. I was on a voluteer fire dept when the call was for a guy who built his own place and had stuffed fibreglas tight against his masonry chimney. The guy with the fire axe pulled out a wad of flaming fibreglas.
I think with both types, dust collected into it is most likely the point of initiation.Excellence is its own reward!
OK. Cellulose will smolder but, if properly treated, not hold a flame. The facing of FG can burn. The binder used to hold the batts together will smolder but is designed, according to the last spec sheet I read, not to hold a flame. None of this makes a difference.
My point is that drywall is a proven and well recognized fire barrier. Neither FG or Cellulose have the stiffness or strenrth to hold back a fire. Once the fire gets into the attic, with exposed joists, trusses, rafters and the like the house is likely to be a total loss.
I was at, working next door, a fire when the fire department arrived. It was an loft type apartment complex with two storey apartments in a row. There were no firewalls in the common attic space. One of the first things they did after checking for victims was to open the roof between the two apartments. According to the firemen I spoke to afterwards the fire had not broken through the drywall ceiling when they got a hole cut and a hose on the roof. Minutes later the fire broke through the ceiling. The 1/2" drywall had held just long enough. Even with a hose in place and soon joined by another they were just barely able to hold the fire, but not the smoke and water, to the one unit.
The firemen were glad the cheif had set up the attack the way he had and all felt for sure the building would have been a total loss had the hoses not been placed to cover the attic. The company I worked for got the job to rewire the place and it was clear that the fire had not broken through the common wall but had billowed into the attic and was set to burn across the entire building. Some of the trusses over the second apartment showed charring and had to be replaced. When the first apartment was renovated the inspector insisted on them continuing the firewall up so that is sealed the attic. He was adamant that it should have been done that way to start.
I never intended to argue against the SR if you took it that way.
With that in mind, The absolute best for this job would be to put in firestop blocking and fill 100% with cells over type X rock, taped. Theroetically speaking, of course.
I agree that any firewall should be extended a few feet above the roof.
Most of the deaths I've seen in home fires were in mobile homes that go up like a butane burner because of the materials they contain, or in old homes with old people who are terrible packrats. They spend years piling up the fuel that becomes their funeral pyre.
Not a good way to go.Excellence is its own reward!
And more inportant than drywall versus an similarily fire-rated thickness of wood is that it be CONTINUOUS. My two firefighting cousins observe that if the envelope is unbroken, the fire is still in the same room when they arrive. But an attic access left open or a light fixture, uninstalled and the whole house is quickly burning.
Who cares about the house being totaled or not? The most important reason for a decent burn time is to allow your family time to wake up and get out of the house.
Note that if you don't have your house inspected as you go (by a private inspector, about $400 total) you'll be stuck doing "owner-financing" as the banks won't touch it.
David Thomas Overlooking Cook Inlet in Kenai, Alaska
David Thomas and Piffin,
I didn't mean to come across as angry. You both have made, from what I understand, made very good points. Lets be careful out there.
PS - Piffin,In case you don't catch my question on the other thread. How did you get the degree mark?