# Residential Smoke detectors



## subelect (Nov 25, 2007)

I stopped by a friend's remodeled house this afternoon and he was showing me around. His electrician is a commercial guy doing the work on the side; which I believe means no AHJ involved. 
In the basement, there are 3 bedrooms off the common room. His electrician installed a hard wired smoke detector in each bedroom, and immediately outside the door to each bedroom. 
So, there are 3 smokes about 4 foot apart from each other in a straight line on the wall of the common room. 
When I asked the owner why, he informed me that the commercial guy told him Code requires a SD inside each bedroom (I agree) and immediately outside the door of each. 
In this 2000 square foot house, with the 4 bedrooms, he has 13 SDs installed and interconnected. 
I know the NEC does not require this, but is there a requirement in the Fire Code for 3 individual SDs so close together? Nothing is going to change the install (sheetrocked and painted), but I would like to know for my own information.
Thanks,
Rick


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## Dennis Alwon (May 9, 2009)

Sounds like the electrician did it correctly. The only problem may be that some sd's don't allow more than 12 units connected together.


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## FastFokker (Sep 18, 2012)

Where I live you could probably get away with 3 smoke detectors in a typical 2200sqft house. We don't require them inside a bedroom, just outside the door in the hallway... therefore multiple bedrooms can be protected by a single smoke detector. 

Of course Fire Code varies drastically by location.


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## crazyboy (Nov 8, 2008)

Each bedroom, hallway and then one on every floor that doesn't have bedrooms.


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## sbrn33 (Mar 15, 2007)

crazyboy said:


> Each bedroom, hallway and then one on every floor that doesn't have bedrooms.


I think there is also something in there about changes in ceiling heights of more than 24 inches also.


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## 347sparky (May 14, 2012)

I have seen 3 smokes installed in one classroom because it was a poured ceiling with poured beams that were 24" tall . The reason is that smoke can become trapped in the ceiling without going under the beam for quite some time, if say a single smoke detector was in the center of the room. Maybe the same application for smoke flowing from the hallway into a bedroom going underneath the door opening.


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## ElectricZombie (Sep 21, 2012)

Here requires SD in each bedroom and one SD/CO2 detector adjacent outside the bedroom within 10' so if all doors to bedrooms are within 10' of 1 SD/CO2 the only one is required.


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## crazyboy (Nov 8, 2008)

sbrn33 said:


> I think there is also something in there about changes in ceiling heights of more than 24 inches also.


Probably, don't run into that often.


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## sbrn33 (Mar 15, 2007)

****, I have the code on my bulletin board at work. I was going to grab it today. Oh well


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## sbrn33 (Mar 15, 2007)

crazyboy said:


> Probably, don't run into that often.


Yea because new homes hardly ever have vaulted ceilings.


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## Wireless (Jan 22, 2007)

One in each bedroom and one in hallway leading to bedroom not longer then 25'


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## wendon (Sep 27, 2010)

Probably makes a difference on the state. In Wisconsin, each level needs a CO2 detector located within 21' of the center line of the bedroom door and a smoke detector in each bedroom/sleeping area.


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## crazyboy (Nov 8, 2008)

sbrn33 said:


> Yea because new homes hardly ever have vaulted ceilings.


Should've said, I don't run into that often. Don't do too many new homes.


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## sbrn33 (Mar 15, 2007)

I don't like to copy and past but here is our citys building code. I believe it is from the 03 International building code.




from310.9.1.4 Location within dwelling units. In dwelling units, a detector shall be installed in each sleeping room and
at a point centrally located in the corridor or area giving access to each separate sleeping area. When the dwelling
unit has more than one story and in dwellings with basements, a detector shall be installed on each story and in the
basement. In dwelling units where a story or basement is split into two or more levels, the smoke detector shall be
installed on the upper level, except that when the lower level contains a sleeping area, a detector shall be installed
on each level. When sleeping rooms are on upper level, the detector shall be placed at the ceiling of the upper level
in close proximity to the stairway.  In dwelling units where the ceiling height of a room open to the hallway serving
the bedrooms exceeds that of the hallway by 24 inches (610 mm) or more, smoke detectors shall be installed in the
hallway and in the adjacent room.  Detectors shall sound an alarm audible in all sleeping areas of the dwelling unit
in which they are located.


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