Tongue and groove woog on bath ceiling

[Dave M]

I have a request to install t+g pine on a bathroom ceiling. Unused attic space above. so ceiling is to be insulated. I was thinking on installing foam board to ceiling and than firing strips followed by the t+g pine.
The attic space will than be insulated.
The question is, is this the way to do it?

[Tim Uhler]

It's been awhile since I did any pine T&G ceilings, although we may get to do it on the house we are currently framing, but not too long ago over at Breaktime forums, someone was talking about it.

The consensus was to drywall the ceiling like normal, and install the pine over that. That will satisfy fire code.

[David Meiland]

drywall the ceiling like normal, and install the pine over that. That will satisfy fire code.

That's what I would do, but here I've put up a fair amount of t&g ceiling directly on the ceiling framing, on the instructions of the builder. It was in a sprinkled house, so that may be the difference.

If you are going to install t&g over drywall, figure out the fastener detail first. The usual way is to nail thru the tongues into the framing with 1/4" crown staples or 15ga finish nails. Having to go thru the rock will make that harder and less effective.

[Sweep8]

I'm trying to think of what the actual purpose of the insulation or the drywall would be. If the attic is designed to be cold enough to cause condensation on the bathroom ceiling there should already be insulation between the attic floor joists. I have never heard of a fire separtaion being required between a living space and an attic in a single family house and I believe T&G wood would meet any draftstopping requirement.

[Andrew R.]

Last time I was in an attic with T&G nailed to framing I could see light at every groove.I have always installed at the very least a 3/8" sheetrock and a coat of mud on the seams just to stop any draft before T&G

[hdrider_chgo]

>>I have never heard of a fire separtaion being required between a living space and an attic in a single family house and I believe T&G wood would meet any draftstopping requirement.<<

I have a hard time believing the fire code would allow you to skip the drywall. I doubt it it would fly around here. And I'd sure want the air barrier that the drywall provides.

Of course you'd only have to fire tape the drywall, not provide a finished surface.

[Allan Edwards]

[QUOTE=hdrider_chgo][QUOTE=Sweep8]I'm trying to think of what the actual purpose of the insulation or the drywall would be. If the attic is designed to be cold enough to cause condensation on the bathroom ceiling there should already be insulation between the attic floor joists. I have never heard of a fire separtaion being required between a living space and an attic in a single family house and I believe T&G wood would meet any draftstopping requirement.

I stand by my original point that this is not only poor construction practice, but would violate building codes in some areas.

hdrider:
Curious as to what specific part of his description arer either poor construction or code violations.

[Allan Edwards]

To build a bathroom ceiling without drywall, and with t&g, in the case of fiberglass insulation, will allow cold air to filter down from the attic through the cracks in the t&g, unless plastic sheeting or other air barrier is used, which was not mentioned.

I'm going to disagree with you here, I think wood over the framing members without drywall is OK. If there is proper insulation I don't think air filtration is an issue. I don't think R value is an issue. I really don't know jack about fire codes in Chicago, so that aside I'm going to agree with Sweep on this one.

I use both 1/2" and 5/8" in my homes.

[hdrider_chgo]

I'm going to disagree with you here, I think wood over the framing members without drywall is OK. If there is proper insulation I don't think air filtration is an issue. I don't think R value is an issue. I really don't know jack about fire codes in Chicago, so that aside I'm going to agree with Sweep on this one.

I use both 1/2" and 5/8" in my homes.

You can agree or disagree about air infiltration, but it is a fact. Fiberglass is not considered an air barrier- that's well-documented, and of course T&G provides no air protection. It may not be a big deal in Texas, but it is in northern climates.

Fire codes aside, protecting combustable wood framing from the spread of fire seems like a good idea, doesn't it?

[Sweep8]

Type-X gypsum wallboard is considered "fire-resistive" but it does not, by itself, have a "fire-resistance rating". Adding it to only one side of a wall or to a ceiling without flooring above does not "create" a fire rating.

It is a great idea to use Type-X gypsum board in a single family house as firestopping between floors, as protection of structural elements, and on separations between spaces, even when it is not required by code, but it is important to understand that it is not much of an improvement over regular gypsum board and does not “create” a fire-resistance rating unless the resulting assembly meets the description of a rated assembly tested under the rules of ASTM E119 and “listed” by an approved testing agency (UL, etc.) or specifically described and given a fire-resistance rating in the building code.

[Dick Seibert]

Just to give you guys some idea of how convoluted the combination of building codes, fire codes, and local amendments is, California is going through the process right now as it tries to make some kind of sense of the International codes. Here is a preamble to the process:
[b]

California Code Adoption


The Office of the State Fire Marshal (SFM), along with other state agencies, is in the process of developing and proposing a new Building and Fire Code for California using the International Building and Fire Codes as the base document. The objective is to develop an adoption package that will include model code language from the 2006 IBC and IFC and current applicable California amendments. The process will utilize a holistic approach to public safety when developing the state construction codes and evaluating the proposed amendments to those codes. The intent is that the final adoption package will include amendments necessary to reasonably maintain a substantially equivalent level of fire and life safety in California.

The State Fire Marshal, by State Law, is responsible for the coordination of the State's fire and life safety codes. The State Fire Marshal must review the proposed regulations of State Agencies that promote fire and life safety before the regulations can be submitted for approval. According to a timetable being considered by the State Agencies, the entire SFM package will be submitted to the State Building Standards Commission in May 2006.

This approach requires that the comparison and subsequent amendment of the IBC to incorporate UBC or CBC provisions be done in a deliberate and thoughtful manner. Another result of this approach could be fewer State amendments, as the decision of which existing amendments to carry over could be made on a case-by-case basis. It also emphasizes a need to either participate in, or, at the very least, closely monitor development of the model code in order to assure the future safety of California.

UPDATE May 15, 2006

The Office of the State Fire Marshal submitted several Parts of Title 24 to the California Building Standards Commission. With these submittals we are beginning the Building Standards Rulemaking Cycle, also knows as Triennial Code Adoption Cycle.

Part 2 - California Building Code (based on the 2006 International Building Code)
# Express Terms (Revised 5/30/06)
# Informative Statement of Reasons (Revised 5/30/06)

Part 3 - California Electrical Code (based on the 2005 National Electrical Code Code)
# Express Terms
# Informative Statement of Reasons

Part 4 - California Mechanical Code (based on the 2006 Uniform Mechanical Code)
# Express Terms
# Informative Statement of Reasons

Part 5 - California Plumbing Code (based on the 2006 Uniform Plumbing Code)
# Express Terms
# Informative Statement of Reasons

Part 9 - California Fire Code (based on the 2006 International Fire Code)
# Express Terms
# Informative Statement of Reasons

Note that we are not even considering several of the International codes, but we are attempting to adopt both the IBC and the IFC.

[Dick Seibert]

Harley Rider:

I don't have the IRC, but do know that a lot was left out, like 5/8" sheetrock and 20 minute doors with closers between garages and homes. I think some of these "oversights" have been corrected in later editions, but I asked some building inspectors if there is a code section requiring "something" behind wood paneling and a guy from Indiana said:

Also see IRC R702.5 - Other finishes, must also meet R315 Flame spread and smoke density.

You might want to check it out.

[Allan Edwards]

HR:

I just built two homes with wood ceilings, I had the carpenters put the wood on top of the framing members. I don't think you get much energy benefits from drywall.

I build in one small City where the fire marshall inspects the smoke detectors before you can get a CO.

[Sweep8]

Dick

In the 2003 IRC:

Garage separation is now 1/2" GWB at the garage side of the shared wall and 5/8" type X GWB at the ceiling (if there is a habitable space above) Doors must be 20 minute rated or solid wood or metal clad all of which are equivalent. It is a mystery to me how to treat a 20 minute fire-rated door in an unrated wall. Does it require a rated metal frame, listed hardware, and a closer? A closer would be disabled the first time someone carried their groceries into the house. I just avoid the issue by using a solid core wood door.

The restrictions for wood wall finishes are that wood veneer and hardboard paneling less than 1/4" thick must have a 3/8" min. GWB backer. All wood paneling materials meet the maximum flame-spread classification of 200 except hardboard/masonite which are border line. So there is no problem with 3/4" pine T&G paneling anywhere and trim is exempt.

You should really get a copy of the ICC codes and read them for yourself; you will probably be suprised since they were written by BOCA, ICBO and SBCCI.

The IRC is very detailed and well written. Not so with the IBC. The IBC is written very much like the UBC which I have always considered to be the most unreadable building code ever written and it was the first one I learned, even took the registration exam with it. I think you're going to like the IBC if CA doesn't hack it up too much.

[Martin Holladay]

Allan,
Keep a close eye on those houses you built. If I understand correctly, there is no ceiling air barrier. The air at the ceiling is under pressure with respect to the outdoors, due to the stack effect. So interior air will be filtering through the gaps between the boards, through the fiberglass batts. In winter the air is likely to encounter a condensing surface, and moisture will collect. The fiberglass batts will gradually turn black, because they will be acting as air filters for the exfiltrating air. At some point you will probably get a callback, and have to install an air barrier -- poly or drywall.