Greg: You raise some interesting questions. I have always considered the materials of the canopy as a whole when deciding whether sprinklers are required. For example, a wood frame canopy, even if faced with cement board (DuRock), in my view is still of combustible construction. I would sprinkler under such a canopy that is more than 4-0 wide. The 2010 edition expands greatly on these situations and offers some options that include wood frame construction that are acceptable..
In your situation I recommend that you find out what material is used for the frame of the canopy and only consider omitting the sprinklers if the frame is non-combustible (steel) or meets one of the three conditions of 8.15.7.3 in the 2010 edition and the vinyl mfr's data sheet publishes a flame spread of 25 or less. Also consider whether combustible storage will be under the canopy. Dave David A. de Vries, P.E., CSP Firetech Engineering Incorporated --- On Wed, 9/8/10, Greg McGahan <[email protected]> wrote: From: Greg McGahan <[email protected]> Subject: Re: vinyl soffits To: [email protected] Date: Wednesday, September 8, 2010, 5:31 PM *8.15.7.2 and** 8.15.7.3 * Limited Combustible which is defined in 3.3 and one of the defining factors is the flame spread less than 25. Plus I was quoting an engineer that just enlightened me as to why heads were not required on a particular canopy. The product I am looking at online appears to meet every description of Limited Combustible in 3.3. I understand I am only looking at one product but it is all I can find with easy to read information. I am not an engineer so I am asking the learned men of the Forum for the correct answer to this situation. Is the engineer correct and heads are not required under a soffit in which (I am only asking about the CEILING) the ceiling is covered in vinyl siding. In all three of the scenarios I am looking at right now, the exterior walls are Non-combustible, brick, concrete and metal siding. OR does the rest of the sprinkler world consider vinyl siding combustible therefore creating a requirement for protection on this one issue alone? 13 does not address what is behind the "exposed finish material", densglass, sheetrock, plywood or bare trusses. I absolutely do not know the answer to this question and I am certainly not trying to manipulate a particular response from the group. However, I am sure that most of us have run into this exact or nearly exact situation before. I have always protected them in the past. Now I have a very high profile local job that will not have them protected which begs the questions - am I right or wrong? So my question remains as stated. I am not adding or subtracting from the text in 13. Is typical vinyl siding considered "limited combustible" or "combustible"? Still appreciative of the help. Greg On 9/8/2010 2:26 PM, David de Vries wrote: > Where does it say that no protection is needed if the siding has a flame > spread of 25 or less? > Is this situation related to a requirement for protection under a canopy of >combustible construction, or if there is combustible storage under the >canopy? Generically speaking, vinyl (PVC) when heated releases chlorine >compounds that inhibit combustion. This is why rigid PVC is treated as a >Group C plastic, rather than Group A, like most plastics we deal with. But >when exposed to an adjacent fire, vinyl siding will burn and fire will go >right up to the canopy or soffit. If there are soffit vents that lead to a >wood frame attic, you can have a disastrous fire. > > Dave > > David A. de Vries, P.E., CSP > Firetech Engineering Incorporated > 2715 Harrison St. > Evanston, IL 60201 > Tel: 847-733-0944 > Fax: 847-866-6255 > > > > --- On Tue, 9/7/10, Greg McGahan<[email protected]> wrote: > > > From: Greg McGahan<[email protected]> > Subject: vinyl soffits > To: [email protected] > Date: Tuesday, September 7, 2010, 8:15 PM > > > In the past we have installed systems for vinyl storage and been met with > very mixed assessments of the criteria it should fall under by members of > this forum and various Engineers of Record. Recently we posed an RFI to an > Arch and Eng design team that stated that at least one vinyl siding product > had a flame spread of 25 or less and therefore would not create a need for > protection under an exterior canopy. I have never heard this before now. > > So the question is that if there is an exterior walkway covered with typical > everyday plain old vinyl siding at the ceiling: would sprinklers be required > if this were the only questionable component? > > There are a myriad of existing such situations in which we happen to find > ourselves at the present time and determining the manufacturer and exact > material would be virtually impossible. > > Thanks for the help as always! > -- _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.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 > [email protected] > http://fireball.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 [email protected] http://fireball.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 [email protected] http://fireball.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)
