Nfpa handbook: " In previous editions of NFPA 13, the protection area per sprinkler was a function of occupancy hazard classification and specific ceiling construction type. This arrangement created difficulties when a type of ceiling construction was not specifically discussed in the standard. Additionally, no guidance was provided for certain combinations of construction type and occupancy hazard. The construction classification approach currently employed – that is, obstructed and unobstructed – ***minimizes that difficulty by dealing only with those construction features that can affect sprinkler performance***."
In your case I don't think a wood roof deck is a factor that would affect sprinkler performance? So is the combustible / noncombustible only referring to the structural members themselves? On Wed, May 6, 2015 at 11:53 AM, Travis Mack <[email protected]> wrote: > Yes. They are more than 70% open. > > As someone said earlier, I have seen this in the past and it was fire > treated wood. However, in this case, it is not for some reason. > > Travis Mack, SET > MFP Design, LLC > 2508 E Lodgepole Drive > Gilbert, AZ 85298 > 480-505-9271 > fax: 866-430-6107 > email:[email protected] > > http://www.mfpdesign.com > https://www.facebook.com/pages/MFP-Design-LLC/92218417692 > Send large files to us via: https://www.hightail.com/u/MFPDesign > > On 5/6/2015 11:52 AM, Sprinkler Academy - C Bilbo wrote: > >> T-Mack, >> My opinion is that you may use 225 sq ft for your spacing here: >> Combustible Unobstructed, exposed members 3 ft or more on center (your >> exposed wood members are infinity apart). Your open truss members are: A) >> not combustible, and B) they do channel heat (please tell me they are at >> least 70% open. that can be the catch here) >> It should be recognized that the above is my opinion as a member of the >> NFPA, and has not been processed as a formal interpretation in accordance >> with the NFPA Regulations Governing Committee Projects and should therefore >> not be considered, nor relied upon, as the official position of the the >> NFPA, nor any of their technical committees. >> >> Sincerely, >> >> >> Cecil Bilbo >> Academy of Fire Sprinkler Technology >> Champaign, IL >> 217.607.0325 >> www.sprinkleracademy.com >> >> [email protected] >> >> >> OUR STUDENTS SAVE LIVES!! >> >> >> >> Date: Wed, 6 May 2015 11:41:47 -0700 >>> From: [email protected] >>> To: [email protected] >>> Subject: Re: Attic >>> >>> That would be my thoughts as well, but there doesn't appear to be >>> wording in the standard that indicates such. Therefore, I will have to >>> defer to the letter of the standard and stick with 130 max spacing. >>> >>> Travis Mack, SET >>> MFP Design, LLC >>> 2508 E Lodgepole Drive >>> Gilbert, AZ 85298 >>> 480-505-9271 >>> fax: 866-430-6107 >>> email:[email protected] >>> >>> http://www.mfpdesign.com >>> https://www.facebook.com/pages/MFP-Design-LLC/92218417692 >>> Send large files to us via: https://www.hightail.com/u/MFPDesign >>> >>> On 5/6/2015 11:19 AM, Brad Casterline wrote: >>> >>>> Unobstructed means just that. >>>> Noncomb. members means no closley spaced, light, fast burning >>>> 'kindling'. >>>> I would vote 225 sf max if my vote counted. >>>> >>>> -----Original Message----- >>>> From: Sprinklerforum [mailto: >>>> [email protected]] >>>> On Behalf Of Travis Mack >>>> Sent: Wednesday, May 06, 2015 12:40 PM >>>> To: [email protected] >>>> Subject: Re: Attic >>>> >>>> That makes sense. I was grabbing for straws. Customer missed it because >>>> of >>>> steel framing. Didn't catch plywood sheathing. I was hoping to be able >>>> to >>>> help cut down sprinkler count. >>>> >>>> Travis Mack, SET >>>> MFP Design, LLC >>>> "Follow" us on Facebook: >>>> https://www.facebook.com/pages/MFP-Design-LLC/92218417692 >>>> Send large files to MFP Design via: >>>> https://www.hightail.com/u/MFPDesign >>>> >>>> Sent from my iPhone >>>> >>>> On May 6, 2015, at 10:25 AM, Eric V. Tysinger <[email protected]> >>>>> wrote: >>>>> >>>>> I would think that the spacing of the members is addressed as potential >>>>> >>>> obstructions. Less than 3' means there are more members between each >>>> sprinkler, so the maximum spacing is reduced to lessen the number of >>>> obstructions. I don't think the combustibility of the members plays a >>>> part. >>>> The table only cares if it is non-combustible or combustible >>>> construction, >>>> obstructed or unobstructed, and the spacing of the members. >>>> >>>>> >>>>> Eric V. Tysinger >>>>> Designer >>>>> Wiginton Fire Systems - Miami, FL >>>>> Email: [email protected] >>>>> Main: 305-888-2402p3416 >>>>> Direct: 305-830-0490 >>>>> Fax: 305-888-3804 >>>>> Mobile: 239-633-9703 >>>>> >>>>> >>>>> >>>>> Confidentiality Notice: >>>>> This e-mail message, including any attachments, is for the sole use of >>>>> the >>>>> >>>> intended recipients and may contain confidential and privileged >>>> information. >>>> Any unauthorized review, use, disclosure or distribution is prohibited. >>>> If >>>> you are not the intended recipient, please contact the sender by reply >>>> e-mail and destroy all copies of the original message. >>>> >>>>> -----Original Message----- >>>>> From: Sprinklerforum >>>>> >>>> [mailto:[email protected]] On Behalf Of >>>> Travis >>>> Mack >>>> >>>>> Sent: Wednesday, May 06, 2015 1:17 PM >>>>> To: [email protected] >>>>> Subject: Re: Attic >>>>> >>>>> That was my question. Does the non combustible framing members modify >>>>> >>>> that, or allow for any changes? I am aware of using that for combustible >>>> members. >>>> >>>>> Travis Mack, SET >>>>> MFP Design, LLC >>>>> "Follow" us on Facebook: >>>>> >>>> https://www.facebook.com/pages/MFP-Design-LLC/92218417692 >>>> >>>>> Send large files to MFP Design via: >>>>> https://www.hightail.com/u/MFPDesign >>>>> >>>>> Sent from my iPhone >>>>> >>>>> On May 6, 2015, at 10:06 AM, Eric V. Tysinger <[email protected]> >>>>>> wrote: >>>>>> >>>>>> Wouldn't table 8.6.2.2.1(a) indicate 130sqft max? >>>>>> >>>>>> Combustible, Unobstructed, with exposed members less than 3'-0 on >>>>>> center. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> Eric V. Tysinger >>>>>> Designer >>>>>> Wiginton Fire Systems - Miami, FL >>>>>> Email: [email protected] >>>>>> Main: 305-888-2402p3416 >>>>>> Direct: 305-830-0490 >>>>>> Fax: 305-888-3804 >>>>>> Mobile: 239-633-9703 >>>>>> >>>>>> >>>>>> >>>>>> Confidentiality Notice: >>>>>> This e-mail message, including any attachments, is for the sole use of >>>>>> >>>>> the intended recipients and may contain confidential and privileged >>>> information. Any unauthorized review, use, disclosure or distribution is >>>> prohibited. If you are not the intended recipient, please contact the >>>> sender >>>> by reply e-mail and destroy all copies of the original message. >>>> >>>>> -----Original Message----- >>>>>> From: Sprinklerforum >>>>>> [mailto:[email protected]] On Behalf Of >>>>>> Travis Mack >>>>>> Sent: Wednesday, May 06, 2015 12:43 PM >>>>>> To: [email protected] >>>>>> Subject: Re: Attic >>>>>> >>>>>> It is not fire treated. I already tried that route. I feel like 225 >>>>>> would >>>>>> >>>>> be acceptable. Which also begs the question, would ex cov be >>>> acceptable? It >>>> is unobstructed construction. I believe the ex cov sprinklers are >>>> allowed >>>> for unobstructed combustible. >>>> >>>>> Just a rare situation. >>>>>> >>>>>> Travis Mack, SET >>>>>> MFP Design, LLC >>>>>> "Follow" us on Facebook: >>>>>> https://www.facebook.com/pages/MFP-Design-LLC/92218417692 >>>>>> Send large files to MFP Design via: >>>>>> https://www.hightail.com/u/MFPDesign >>>>>> >>>>>> Sent from my iPhone >>>>>> >>>>>> On May 6, 2015, at 9:21 AM, Todd - Work <[email protected]> wrote: >>>>>>> >>>>>>> Good question. I think you could go to 225, but the Book doesn't >>>>>>> address it. I assume the plywood is not fire treated? Most of the >>>>>>> times I see this arrangement, the plywood is treated. >>>>>>> >>>>>>> Todd G Williams, PE >>>>>>> Fire Protection Design/Consulting >>>>>>> Stonington, CT >>>>>>> www.fpdc.com >>>>>>> 860-535-2080 (ofc) >>>>>>> 860-608-4559 (cell) >>>>>>> Sent using CloudMagic >>>>>>> [https://cloudmagic.com/k/d/mailapp?ct=ti&cv=6.0.64&pv=8.2] >>>>>>> On Wed, May 6, 2015 at 12:04 PM, >>>>>>> [email protected] >>>>>>> <[email protected]> wrote: >>>>>>> For an attic with light gauge steel trusses spaced 24" on center and >>>>>>> plywood deck sheathing, would the spacing be limited to 130 sq ft or >>>>>>> would 225 be acceptable? Slope is 3:12. >>>>>>> >>>>>>> Travis Mack, SET >>>>>>> MFP Design, LLC >>>>>>> "Follow" us on Facebook: >>>>>>> https://www.facebook.com/pages/MFP-Design-LLC/92218417692 >>>>>>> Send large files to MFP Design via: >>>>>>> https://www.hightail.com/u/MFPDesign >>>>>>> >>>>>>> Sent from my iPhone >>>>>>> _______________________________________________ >>>>>>> Sprinklerforum mailing list >>>>>>> [email protected] >>>>>>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprink >>>>>>> l er.org _______________________________________________ >>>>>>> Sprinklerforum mailing list >>>>>>> [email protected] >>>>>>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprink >>>>>>> l >>>>>>> er.org >>>>>>> >>>>>> _______________________________________________ >>>>>> Sprinklerforum mailing list >>>>>> [email protected] >>>>>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl >>>>>> er.org _______________________________________________ >>>>>> Sprinklerforum mailing list >>>>>> [email protected] >>>>>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl >>>>>> er.org >>>>>> >>>>> _______________________________________________ >>>>> Sprinklerforum mailing list >>>>> [email protected] >>>>> >>>>> >>>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>>> >>>>> _______________________________________________ >>>>> Sprinklerforum mailing list >>>>> [email protected] >>>>> >>>>> >>>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>>> _______________________________________________ >>>> Sprinklerforum mailing list >>>> [email protected] >>>> >>>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>>> >>>> _______________________________________________ >>>> Sprinklerforum mailing list >>>> [email protected] >>>> >>>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>>> >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>> >> >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >> > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
