Thought someone else like John Drucker would jump in on this, but since he has not, I will give it a try. As far as the UL standard fire test for structural elements is concerned, there is no such thing as a one-hour floor or a one-hour ceiling. There are rated ceiling-floor assemblies and there are rated ceiling-roof assemblies. So if those trusses in the middle of your ceiling floor sandwich are structurally supporting that floor and that ceiling, then the whole thing is an assembly and would be tested by UL as such. Sounds like the person telling you that he has a one-hour floor on top and a one-hour ceiling below does not really understand the fire testing that such a thing must pass. All of that is beside the point when it comes to sprinkler protection of a combustible concealed space. Unless there is a specific exception in the applicable building code, 13 will be the governing document as glc and others have pointed out. You are quite right to step away from the crowd and stick with what is in the standard. There is not enough liability insurance in the world to cover a fire that gets into to such a space and spreads throughout the building. And they do sometimes get into such spaces!!
Dave David A. de Vries, P.E., CSP Firetech Engineering Incorporated --- On Mon, 6/1/09, Dewayne Martinez <[email protected]> wrote: From: Dewayne Martinez <[email protected]> Subject: RE: Combustible rated floors To: [email protected] Date: Monday, June 1, 2009, 8:02 AM 1hr ceiling attached to the bottom of the truss and a 1hr floor on top. Truss are normally 16 or 24in OC. No flame retardant material in the truss construction. So far, we have lost jobs in 2 municipalities where the AHJ has accepted this. I have been telling my salesmen that is is not worth the liability to omit these sprinklers and to keep them in our bid. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Todd Williams Sent: Monday, June 01, 2009 7:30 AM To: [email protected] Subject: Re: Combustible rated floors Is there a 1 hour rated ceiling below the truss and a 1 hour rated floor above the truss? What is the truss spacing? Are they made with fire retardant lumber? If it doesn't meet any on the exceptions in 8.14, then it should be sprinklered. Are the AHJs accepting this? At 07:56 AM 6/1/2009, you wrote: >We have a growing trend up here in which contractors are not installing >sprinklers in combustible floor spaces (open wood truss) simply because >there is a 1hr rated floor and ceiling assembly which sandwiches the >combustible space. We have been including sprinklers for these areas >in our bids but have been loosing work because of this. Am I missing >something and can sprinklers be omitted? >Thanks, >Dewayne Martinez >Design Build Fire Protection >New Berlin, WI >_______________________________________________ >Sprinklerforum mailing list >http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >For Technical Assistance, send an email to: >[email protected] > >To Unsubscribe, send an email >to:[email protected] >(Put the word unsubscribe in the subject field) Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut www.fpdc.com 860.535.2080 _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
