smoke detector location

[wayne123]

I know this is not a NEC question, but I'm going to ask it anyway. I am wiring a house with a cathedral ceiling in the LR. It is a post and beam contructed house. The LR is approx. 70' long and the ceiling is about 25' high. I am considering installing the smokes @ each end of the room within the required 4" to 12" "rule" below the ridge beam. Is this OK? I am also concerned about the homeowner servicing them. Anyone know more about the locations.

 

[websparky]

Re: smoke detector location

You have the right idea except you will need 3 smokes. They typically have a 30' maximum coverage diameter/area.

Usually, some of the manufacturers have their specs and diagrams with the smoke.

 

[wayne123]

Re: smoke detector location

Thanks Dave. There is no way that I can get another smoke in that area because the ceiling is tongue and groove and the only place I can put them is in the gable ends of the room. There is a loft in the room that has the only bedroom in the house so I am going to put one smoke in there so there will actually be 3 smokes in that room to help cover the 30' rule.

 

[websparky]

Re: smoke detector location

You are welcome!

Sounds good to me.
Smokes are not an exact science. They are there for an early warning. There are times smokes will not detect certain types of fires until the area is involved to a large degree. We place them the best we can and hope we never need them!

 

[mp101]

Re: smoke detector location

The 30' smoke coverage guide will decrease once you exceed over 10' in height. For a 25' mounting location, the spacing factor reduces by approx 0.46 multiple of the listed spacing.

Mike

 

[jerryb]

Re: smoke detector location

Good point Mike, but don't forget that the spacing increases when the room is not square. The original post only said that he room was 70' long.

I can't paste the diagram into this response but the code section is NFPA 72, Appendix A, Figure A.5.6.5.1.2

 

[eprice]

Re: smoke detector location

Originally posted by wayne123:
I know this is not a NEC question, but I'm going to ask it anyway. I am wiring a house with a cathedral ceiling in the LR. It is a post and beam contructed house. The LR is approx. 70' long and the ceiling is about 25' high. I am considering installing the smokes @ each end of the room within the required 4" to 12" "rule" below the ridge beam. Is this OK? I am also concerned about the homeowner servicing them. Anyone know more about the locations.

It depends on what you mean by "OK". If you are asking whether this will satisfy the code, it depends on what building code applies to single family dwelings in your area. Both the IRC and the UBC require a smoke detector in every bedroom and in the area just outside the bedrooms. There must be at least one smoke detector on every floor. I assume LR means living room? There is no specific requirement in either of these two codes for any smoke detector in the living room, unless a bedroom opens onto the living room, and then only in the area(s) near where the bedroom(s) enter.

[ April 08, 2004, 03:22 PM: Message edited by: eprice ]

 

[a.wayne3@verizon.net]

Re: smoke detector location

Smoke detectors only fall under the 2002 NEC as far as being arch fault protected 210.12 B,and also must be installed in accordance with manufacturers instructions as well as local codes
I can only tell what we are required to dne inside each bed room,one within 10 ft of the door leading out of that bedroom.Not within 3 ft of forced air system vents supply as well as returns,also bath room doors.One at the top of stairs and one at the bottom.Don`t forget to protect the highest part of the house as well.That requires only one so if there are multiple bedrooms entering a vaulted ceiling room then only one of the required to be high the others may be wall mounted to be within required distance from the bedroom.These are the requirements here.Some local codes may require more or less.Check with the building inspector in your area since this is there call on a final C.O. inspection.

 

[davedottcom]

Re: smoke detector location

Wayne, I used to wire alot of those Post & Beam homes when I lived in PA. They are ALWAYS a challenge but something to be proud of when it's complete! To get electric to some of those "Impossible" locations I would actually use a router and make a groove in the top of the tounge and groove floor boards, run the wire in it, and use about 50 nailplates across the floor to protect the wire. Of course I was only able to do this after "clearing" it with the builder, making sure they were going to put carpet in the 2nd floor room (usually a bed rm) instead of having the exposed tounge and groove "floor" exposed. If it's in the 2nd floor ceiling of the home you can run the wire on top of the ceiling tounge and groove (pvc across the roof)before they put the layer of insulation down. The roofers notch out the insulation panels to cover the pvc pipe.
There was never anywhere "Impossible" to get to! A time consuming-pain in the ***, yes, but there was always a way! Hope this helps in the future!
Dave

 

[hurk27]

Re: smoke detector location

Here is some of Indiana's state code on smoke placement requirment's

Indiana Administrative Code Page 35
675 IAC 14-4.2-31 Section R317; smoke alarm
Authority: IC 22-13-2-2; IC 22-13-2-13; IC 22-11-18
Affected: IC 22-12; IC 22-13; IC 22-14; IC 22-15; IC 36-7
Sec. 31. Delete the text of SECTION R317 and substitute to read as follows:
R317.1 Labeling. Each smoke alarm shall be listed.
R317.2 Required smoke alarm locations. At least one (1) smoke alarm shall be installed in each of the following locations:
(a) In the living area remote from the kitchen and cooking appliances. Smoke alarms located within twenty (20) feet (six and
one-tenth (6.1) meters) horizontally of a cooking appliance must incorporate a temporary silencing feature or be photoelectric
type.
(b) In each room designed for sleeping.
(c) On the ceiling of the upper level near the top or above each stairway, other than a basement stairway, in any multistory
dwelling. The alarm shall be located so that smoke rising in the stairway cannot be prevented from reaching the alarm by an
intervening door or obstruction.
(d) On the basement ceiling near the stairway.
R317.2.1 Alterations and additions. When interior alterations or additions requiring a permit occur, or when one (1) or more sleeping
rooms are added or created in existing dwellings, the individual dwelling unit shall be provided with smoke alarms located as
required for new dwellings; the smoke alarms shall be interconnected and hard wired.
EXCEPTIONS: 1. Smoke alarms in existing areas shall not be required to meet the requirements of R317.5 where the
alterations do not result in the removal of the interior wall or ceiling finishes exposing the structure unless there is an attic,
crawlspace, or basement available which could provide access for hard wiring and interconnection without the removal of
interior finishes.
2. Repairs are exempt from the requirements of the section.
R317.3 Prohibited smoke alarm locations. A smoke alarm required under this section shall not be placed:
1. within three (3) feet (nine hundred fourteen (914) millimeters) horizontally from any grille moving conditioned air within
the living space; or
2. in any location or environment that is prohibited by the terms of the listing.
R317.4 Mounting requirements. Smoke alarms required by SECTION R317.2 shall be mounted in accordance with their listing,
instructions, and the requirements of this section.
R317.4.1 Flat Ceilings. In rooms with flat, peaked sloping or single slope ceilings with a slope of less than 1.5/12, smoke alarms
shall be mounted either:
1. on the ceiling at least four (4) inches (one hundred two (102) millimeters) from each wall; or
2. on a wall with the top of the alarm not less than four (4) inches (one hundred two (102) millimeters) below the ceiling and
not farther from the ceiling than twelve (12) inches (three hundred five (305) millimeters) or the distance from the ceiling
specified in the smoke alarm manufacturer’s listing and instructions, whichever is less.
R317.4.2 Peaked Sloping Ceilings. In rooms with peaked sloping ceilings with a slope of 1.5/12 or greater, smoke alarms shall be:
1. mounted on the ceiling or wall within three (3) feet (nine hundred fourteen (914) millimeters), measured horizontally, from
ONE AND TWO FAMILY DWELLING CODE
the peak of the ceiling;
2. at least four (4) inches (one hundred two (102) millimeters), measured vertically, below the peak of the ceiling; and
3. at least four (4) inches (one hundred two (102) millimeters) from any projecting structural element.
R317.4.3 Single Slope Ceilings. In rooms with single slope ceilings with a slope of 1.5/12 or greater, smoke alarms shall be:
1. mounted on the ceiling or wall within three (3) feet (nine hundred fourteen (914) millimeters), measured horizontally, of
the high point of the ceiling; and
2. not closer than four (4) inches (one hundred two (102) millimeters) from any adjoining wall surfaces or any projecting
structural element.

 

[wayne123]

Re: smoke detector location

Thanks Guys, Good info!

 

[eprice]

Re: smoke detector location

Reading through the amended code that hurk27 posted, it appears that in Indiana one (but only one) smoke detector is required in the living room.

 

[laengineer]

Re: smoke detector location

NFPA 72, which governs the installation of smoke detectors indicates that if the beams are greater than 12 inches in depth, then the area between the beams must be treated as a separate space. The theory is that the "pockets" created by the beams can trap the smoke within the pocket. So count the number of pockets created by the beams and treat accordinly. Hope this helps.

 

[macmikeman]

Re: smoke detector location

Hi, I am replying to Dave's post about nail plates. Dave I have to do the same thing a few times each year. What I do is go to a sheetmetal shop around once a year and order up 300 linear feet of #12 ga metal strips cut 1-1/2" wide by 10' long. You can route a channel in the tounge and groove and lay a strip over the wire. Next you can alternatly use short roof nails to secure the strip, by nailing just on the side of the strips. The big nail heads overlap the metal and hold it down. In my area they like us to use UF cable when we do this up on the roof prior to the black paper and shingles going onto the roof.

 

[a.wayne3@verizon.net]

Re: smoke detector location

Mac i can understand protecting the wire ,but why UF ???Its in a dry location or was this an inspector satisfy move.Dave we all know some installations are unreal.We did a Tiki bad 5/4 t&g ceiling all wired fron on top 3 " insulated sheathing cut out for emt but they still drilled sq. head screws into 4 sqs and emt.

 

[davedottcom]

Re: smoke detector location

I here ya Wayne! I've already found a screw that was drilled right thru a nailplate and got to the wire! Nothing is safe from everthing, it's just not possible. We can only try to make it difficult for someone to damaged our work, not impossible. But hey, there's a lot of money to be made in repair work!!! :roll:

Dave