The use of heat detectors vs smoke detectors in an occupied building in construction

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watts-ae

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Location
Buffalo, New York
I have a building in construction (assembly, alteration level 2) that will be occupied during construction. The contractor would like to provide heat detectors to replace the smoke detectors in the construction zones instead of a fire watch. Can any one point me to the right code in NFPA 72 that would allow this to happen? I have heard people say the code allows this but I can?t find anything on it?
I am no means a fire alarm expert so if any of you out there are I am waiting to hear from you.
 
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nhfire77

Senior Member
Location
NH
72 does not address fire watches for construction purposes. Although the system is impaired and that may justify a fire watch, it's not an occupied space. Is there a true fire wall/seperation between construction and occupied spaces?

Smoke detectors are not permitted to be installed during construction of a new building. If, they were to use them, prior to system commissioning, they are required to be replaced, not just cleaned. In a renovation this should also apply. I'm assuming this renovation Will most likely generate large amounts of dust. In this case smoke detectors would not be appropriate to remain in place.

Heat detectors would be an acceptable method of detection in a finished space that had large amounts of dust, under construction is a gray area and of course of great concern regarding fire safety. The type of occupancy and the life safety hazards would dictate what you would use, if any. I would recommend discussing this with the building owner the tenant. Then get the blessing from the AHJ on the plan.

If this is taking place in a major city such as Los Angeles New York or Houston they will have a code defining when a fire watch is required other similar cities have similar. Again check with the fire prevention Bureau Of the fire department
 
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MichaelGP3

Senior Member
Location
San Francisco bay area
Occupation
Fire Alarm Technician
You made good points, nhfire77. One nitpick, and not to correct you but just to bring other readers onto the same page: heat detectors are not life safety devices. They are for property protection only. What ever your AHJ desires or approves doesn't change this. Having said that, I've seen temporary heat detectors installed in construction areas (say one wing or one floor) of an occupied building, but these construction areas are only occupied by construction personnel. Not the same situation as the OP's.

Some alternatives:

1.) Is the building sprinklered, and are the sprinkler heads 'live' in the project area? This would provide automatic detection (from the waterflow switch), evacuation, fire department response (assuming the facility is monitored), and suppression.

2.) Existing smoke detectors can be covered by plastic dust covers furnished by the manufacturer. Every detector ships with one; hopefully these were turned over to the building when the original system was commissioned. The AHJ may allow the contractor to cover the smoke detectors when he arrives and takes them down (carefully, as there might be alarm causing dust on the lip of the cover!) at the end of each shift. Under no circumstances allow anyone to use duct tape to cover smoke detectors. There are fumes that outgas from the adhesive in duct tape that attack internal components in some smoke detectors. In cases where I've seen this, the detectors could not be cleaned. They had to be thrown out.

3.) Temporary heat detectors can be augmented with temporary horn or speaker/strobes and pull stations.

Good luck with your project.
 
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watts-ae

Member
Location
Buffalo, New York
Thank you this is what i was looking for, could you please give me some code to back up # 3?

This is what i was trying looking to do, i just can't convince the AHJ that it mets code.
 
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nhfire77

Senior Member
Location
NH
watts-ae said:
Thank you this is what i was looking for, could you please give me some code to back up # 3?

This is what i was trying looking to do, i just can't convince the AHJ that it mets code.
Click to expand...

Its not in the code as a prescriptive item, it was a suggestion.


Sounds like the AHJ wants smokes up during construction, if he has the discretion that's what you have to do, and here is what you have to do. (assuming the alarm transmits to the FD, after 4 or 5 false alarms and you possibly getting fined for the false alarms, maybe you can revisit it :thumbsup: )

2011 NFPA 72 Section 17.7.1.11* Protection During Construction

17.7.1.11.1 Where detectors are installed for signal initiation during construction, they shall be cleaned and verified to be operating in accordance with the listed sensitivity, or they shall be replaced prior to the final commissioning of the system.

17.7.1.11.2 Where detectors are installed but not operational during construction, they shall be protected from construction debris, dust, dirt, and damage in accordance with the manufacturer’s recommendations and verified to be operating in accordance with the listed sensitivity, or they shall be replaced prior to the final commissioning of the system.

17.7.1.11.3 Where detection is not required during construction, detectors shall not be installed until after all other construction trades have completed cleanup.


Edit: The AHJ, or the adopted code and amendments define whether they need to be there during construction, despite common sense.
 
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