combustible space sprinkler req. combustible space sprinkler req. sremac (Mechanical) (OP) 25 Jul 17 00:35 Hi, It is a building with roof trusses and drop ceiling. 5/8" drywall attached to bottom of trusses. Do we need protection above ceiling? I attached pdf from arch. drawings. Thanks, http://files.engineering.com/getfile.aspx?folder=e0eba87c-84ce-4569-8933-2f RE: combustible space sprinkler req. cdafd (Specifier/Regulator) 25 Jul 17 03:51 I take it by the title, the trusses are made out of wood?? If so yes sprinkler protection is required. Unless you fill the Entire space with non combustible insulation. RE: combustible space sprinkler req. sremac (Mechanical) (OP) 25 Jul 17 13:11 I've seen office building where they attached drywall to trusses, fire stopped and they did not put sprinklers above. I guess AHJ was making they own rules or am I missing something here :) RE: combustible space sprinkler req. TravisMack (Mechanical) 25 Jul 17 16:22 If you have SOLID members like 2x or TJI and sheetrock to the bottom then you can omit sprinklers in the concealed space. You may end up with a 3000 sq ft design area if certain criteria are not met in those instances. In the picture you provided, you are going to require SPECIALLY LISTED concealed space sprinklers. These come with their own requirements in the sprinkler data sheet. You will possibly need draft curtains (not draft stops) depending on full height walls and such. Review the criteria carefully on those sprinklers. Travis Mack MFP Design, LLC www.mfpdesign.com "Follow" us at https://www.facebook.com/pages/MFP-Design-LLC/9221... RE: combustible space sprinkler req. cdafd (Specifier/Regulator) 25 Jul 17 18:57 You would have to cover every stick of wood in the attic area, with Sheetrock Does not matter, but what is the use of the building?? RE: combustible space sprinkler req. stookeyfpe (Specifier/Regulator) 25 Jul 17 20:02 What is the building's construction classification based on the jurisdiction's building code? I can't tell if this Type V (combustible) or Type II (noncombustible). If it's Type III (mixed) what is the material of construction for the trusses? RE: combustible space sprinkler req. sremac (Mechanical) (OP) 25 Jul 17 22:47 I totally agree with statement that area needs to be sprinklered , just don't get where architects or AHJ think if you rock bottom of trusses with we can eliminate sprinkler protection above. I think that next thread has same question..