Charleston home inspector discusses smoke alarm requirements.

Submitted by Ray Thornburg on Tue, 10/02/2012 - 12:45

Smoke Alarm Requirements

Although the required number and location of smoke alarms have changed over the years most people will agree that every home should have a smoke alarm. Older homes do not have to be upgraded to the new codes unless there are major renovations as outlined in the code. South Carolina uses the 2006 code and here are their requirements. paraphrased-

  • "smoke alarms shall be installed in each sleeping room"
  • " Outside each separate sleeping area in the immediate vicinity of the bedrooms"
  • " On each additional story of the building including basements but not including crawl spaces and attics. 
  • Shall be interconnected so they all sound off at the same time
  • Shall receive their primary power from the building wiring and have a battery backup.


References... IRC 2006 313.1-3

Carbon Monoxide Alarm Requirements 

Carbon monoxide is an invisible odorless gas produced by fuel burning appliances. It can be deadly so a carbon monoxide detector is a good idea anytime there are fuel burning appliances in your home or an attached garage.  This excerpt is from the 2012 IRC.

"For new construction an approved carbon monoxide alarm shall be installed outside of each separate sleeping areas in the immediate vicinity of the bedrooms in dwelling units within which fuel fired appliances are installed and in dwelling units that have attached garages."

References .... IRC 2012 315.1

  • Propane is heavier than air.
  • Natural Gas is lighter than air.
  • CO is about 3% lighter than air. In addition -  it is thought that since CO (carbon monoxide) is a product of combustion it will be hotter and thus lighter than the surrounding air making it rise. With this in mind the placement of a CO detector can be roughly the same as smoke alarms unless the manufacturer's directions say differently. Typically a smoke detector is installed about a foot down from the ceiling.

Here is some more information about smoke alarms from NFPA (the National Fire Protection Association).

Smoke alarms should be tested occasionally (once a month) and most experts indicate that it is a good idea to replace them every 10 years. If your detectors are turning yellow....then consider replacing them.

Blue Palmetto Home Inspection Serves the entire Charleston Lowcountry area!


Submitted by Ray Thornburg on Tue, 10/02/2012 - 12:45