Ask Mr. Inspector

Dear Keith,

I frequently recommend to my clients that they should add smoke alarms. Is there a code requiring smoke alarms to be added to existing homes? On a related note, I heard some smoke alarms contain radioactive materials. Are they dangerous?

Thanks,
Bob, CT

Thanks for the questions Bob. First let’s talk about the requirements for smoke alarm location in new construction. According to the 2006 International Residential Code (R313.2), smoke alarms are required to be installed in each sleeping room, outside each separate sleeping area in the immediate vicinity of the bedrooms, and on each additional story of the dwelling. Additionally, the alarms must be hard wired, interconnected, and have a battery back-up. Interconnected means that when one alarm is activated all of the alarms in the required locations must also activate.

The IRC goes on to mandate that when alterations, repairs, or additions requiring a permit occur, the home must be equipped with smoke alarms according to the requirements for new construction mentioned above. There are two exceptions to the retrofit requirement. One, if the there is no attic, crawl space, or basement that could provide access for hard wiring and the alterations do not result in the removal of interior wall or ceiling finishes. Two, if the alterations to the existing structure only involve the exterior surfaces, doors, windows, porches, or decks.

The two types of smoke detectors that are most common are the photoelectric and ionization chamber detectors. The ionization chamber detector does contain a small disk made of americium-241 which is a radioactive material. Using terms and explanations that evoke faded memories of studying for the radon measurement exam, the EPA rates the exposure as “negligible” and gives no recommendation to avoid these devices.

The National Fire Protection Association has numerous additional recommendations regarding the installation, testing, maintenance, and replacement of smoke alarms including:

• Ceiling mounted alarms should be installed at least four inches away from the nearest wall.
• Wall mounted alarms should be installed four to twelve inches away from the ceiling.
• Test smoke alarms once a month.
• Regularly vacuum or dust the smoke alarms.
• Change the batteries every year.
• Replace smoke alarms every ten years.

If you are interested in providing your clients with these recommendations, you may direct them to www.nfpa.org or provide them with document #5077 from the Consumer Product Safety Commission.

Keith Ruehl is currently Director of Training for U.S. Inspect, LLC. His previous position was director of operations for the eastern U.S. Keith was owner of a multi-inspector firm in Florida for approximately ten years prior to joining U.S. Inspect in 1998. Keith has served on the national board of directors and as a national officer for the American Society of Home Inspectors. A few of Keith's credentials include:

residential contractor, roofing contractor, building inspector, electrical inspector, and pest control operator. Additionally, he earned an MBA from Nova Southeastern University.