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Smoke Detector Install Cathedral Ceilings and SIPS

Posted by wxtrender (My Page) on
Wed, Oct 16, 13 at 10:17

Ok trying to get one answer. SIP supplier and General Contractor disagree on smoke detector locations.

We are in PA and under 2009 ICC Building Codes.

New Construction, single family residence.

Trying to find out once and for all if the bedroom smoke detectors can be installed on the walls of a bedroom with a cathedral ceiling? SIP guy says wall mounted is ok as long as the top edge of the smoke detector is 4" below the peak of the ceiling but not more than 12". General Contractor says it needs to be ceiling mounted.

Wall mounted is not an issue, but ceiling mounted means we'd need to plan ahead for a wire chase in the panel to account for the ceiling mounted smokie.

Any help is appreciated.

Follow-Up Postings:

RE: Smoke Detector Install Cathedral Ceilings and SIPS

This is NOT an electrical code issue. The electrical code doesn't address this issue.

A single family residence appears to allow them to be on the wall. The few places it mentions ceiling it also says "or wall". The ICC pretty much dumps you on NFPA 72, which unfortunately, I don't have (and the NFPA website is currently crocked and I can't get at the free one).

RE: Smoke Detector Install Cathedral Ceilings and SIPS

Be sure to learn and follow the local code(s). It may be in multiple codes, all applicable to your premises, and they may conflict with each other.
NC building code permits smoke detectors on ceiling or wall, with specifications for placing them. But the housing codes for some NC cities requires them on the ceiling only. And different departments enforce the codes. So you build your NEW house with detectors on the walls. Building inspector approves and issues the CO. Then the housing inspector declares your NEW house to be uninhabitable. Your out? The building code requires that smoke detectors be hard-wired to the electrical system. The housing code permits use of battery operated detectors. So you add battery-operated units on the ceilings and now are in compliance. And you have detectors out the wazoo.
Ain't gubmint wonderful?

RE: Smoke Detector Install Cathedral Ceilings and SIPS

I finally got the NFPA 72 to load (NFPA moronic site). Smokes need to be on the ceiling or on the wall within 12" of the ceiling.

As pointed out, your local authority may have different ideas.

RE: Smoke Detector Install Cathedral Ceilings and SIPS

Put in a call to the head of the local fire department and ask him about your problem. On a wall, "within 12" of the ceiling", is one foot away from where the ceiling meets the wall and is so specified because fresh air can be trapped in space between the top of the smoke and the ceiling surface, delaying an alarm. The trapped fresh air space is likely to have more depth at the apex of a cathedral ceiling and a smoke detector placed there would only be activated after quite a bit of smoke was generated, (to travel that high and then to overcome the pressure of the trapped air.) There is also "stack effect" to be considered, but it's unlikely in most single family homes.

If the the code and inspectors permit it and hold you to a standard that requires placement of a notification device at the highest point in the room, ask if a heat detector can be substituted.

RE: Smoke Detector Install Cathedral Ceilings and SIPS

No way by every code I've seen (including the ICC mentioned in the original post). You must have SMOKES in the sleeping areas. You can put additional heat detectors in if you want (and they're mandated in places like furnace rooms).

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