I appreciate your insight David, but again, I just want to be certain
of the intentions of NFPA #13.
On 9/9/2010 12:01 PM, David de Vries wrote:
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)
--
_______________________________________________
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)
