What You Can’t See Could Hurt You

Friday, May 14, 2010

Renovations in older limited combustible structures present many fire protection challenges.  The architectural need to be sensitive to aesthetics compounds the challenge when dropped ceilings and soffits are created to enhance appearance to limit the visual impact of the piping, ductwork, conduits and equipment.  When combustible or limited combustible construction is concealed, NFPA 13, the Standard for the Installation of Sprinkler Systems, defines these spaces as combustible concealed spaces that must be protected with automatic sprinklers.  There are exceptions that allow the omission of sprinklers in these areas.  However, almost all result costs above the cost of installing sprinklers.  With that said, NFPA 13 also required that where these space are three feet or less in height they must be protected with sprinklers listed for that purpose.  The listing information for these “special application” sprinklers stipulates that draft curtains or full height walls must be provided to create areas within the combustible concealed space not greater than 1,000sq/ft.  Although most small concealed may meet this requirement, interstitial spaces between floors and attic areas in flat roof buildings most likely will not.  Obviously, creating these limited areas within combustible concealed spaces needs to be considered during design.  If not, your project could be hurt by the added cost and delay in construction that will occur when they need to be created at a later date.