Using the 2007 Edition
Q: I have an assembly occupancy where the owner wants smoke detectors but the ceiling is cast concrete with ‘honeycomb' pockets in it, making 4 foot by 8 foot inverted boxes about 20 inches deep on the ceiling. If I have to install a detector in each space, then the owner will choose not to install these optional detectors. Our state has adopted the 2002 version of NFPA 72.
A: The 2002 edition doesn't specifically address the ceiling type you have described. However, section 5.7.3.1.2 states that you must consider “ceiling shape and surface” when determining spacing of smoke detectors.
Placing a detector in each beam pocket would certainly cover it. Yet, it sounds like it may be a bit too much for your client. Also, codes don't require this occupancy to have open area smoke detectors, so the amount of detectors and their location will be the customer's choice (unless this building is in Nassau County , N.Y. ).
I suggest you use the new 2007 edition of NFPA 72, since it does address these ceilings. You can use it as proof of your compliance with section 5.7.3.1.2 of your 2002 edition. The 2007 edition states that for level “waffle or pan-type ceilings” with pockets no deeper than two feet, and beam spacing of no greater than 12 feet center-to-center, then you can use the rules for smooth ceiling spacing. This includes those rules permitted for irregularly shaped areas, where the spacing between detectors is permitted to be greater than the selected spacing, provided the maximum spacing from a detector to the farthest point of a sidewall or corner is not more than 0.7 times the selected spacing.
Also, the 2007 edition gives you the choice of mounting the smoke detectors on the recessed ceiling or on the bottom of the beams. (See NFPA 72, 2007, section 5.7.3.2.4.2.) What this means is, you can pretend your ceiling is flat/smooth, measuring its height to the bottom of the projections, then use this measurement in Table 5.6.5.5.1 to reduce the detector's installed spacing. Bullet-proof logic.
Can I Get a Witness?
Q: Lately, when we call in to put the system on test with the local fire dispatch, the chief/inspectors say I can't perform any testing unless one of them is present. It means having to constantly change our company schedule to fit the times these guys can be there. Do I really have to have these fire departments witness fire alarm tests and inspections?
A: All fire codes give the fire official the right of entry when there is reasonable cause to investigate suspected violations, perform inspections and otherwise enforce the provisions of the fire code. Their request must be at “reasonable times,” they must present credentials and have the owner's permission. In our case, technicians provide written reports that detail the owner's code compliance with the routine test/inspection requirement. These reports must be made available to the inspector upon their request. To state that “no testing can take place without my presence” is unreasonable. At the very least, you should put a clause in your fire alarm test and inspection contract stating that if any fire inspector needs to be in attendance and witnesses the inspections, it will cost an extra $XXX, per occurrence. There's nothing in any code or standard that states they must witness every on-going routine test and inspection.
