Class C roof assembly

[nickmcb]

In my area, Nevada County, CA the building department requires a Class C roof assembly. Class A/B/C roof assemblies are testing using UL 790 ASTM E 108 standards. Below is an email I sent to Calfire and their response:

Nick,

I have provided the link to the Flame-Retardant Program for our review. It is primarily for tents and decorative materials such as drapes, curtains, awning, etc. There is a difference between test requirements for wildland interface and the test conducted required by Title-19 Chapter 8. These materials would not be considered roofing materials.

Thank you for contacting the us with your questions.

http://osfm.fire.ca.gov/strucfireengineer/strucfireengineer_flameretardant


Thomas Campbell
Deputy State Fire Marshal III
CAL FIRE
Office of the State Fire Marshal


From: Nicholas McBurney [mailto:[email protected]]
Sent: Friday, December 14, 2018 3:08 PM
To: CALFIRE SFM Flame Retardant Program <[email protected]>
Subject: Question on Yurt fabric rating

Good afternoon,

I have a registered flame resistant product listing F-12241 being proposed as the exterior covering of a Pacific Yurt including the roof. We have determined that a u-occupancy building that does not need to comply with the Wildland Urban Interface requirements (<50’ from the residence) must have a minimum class C roof assembly. My understanding is that fabric is tested using different testing standards then roofing material. As such, we have not allowed the use of this fabric as an equivalent. Does CalFire certify this fabric as meeting a class A, B or C roof assembly requirement?


Here is my question: Has anyone put a Class A/B/C rated roof assembly on a lightweight lattice style yurt? If so, can you send me the listed assembly?

[Jafo]

I am going to tag

Pacific Yurts

on this. They may have more info.

[jeritchie]

OK, to make this ever clear the "CLASS C RATING" is talking about the total assembly of the roof "system"

so that is:
rafters
liners

insulation

and outer cover

Yurts of America

ONLY uses

Duro-Last

roofs, we haven't done vinyl roofs in almost 10 years.


Due to this I know that

Duro-Last

roofs does meet the "Class C" request for roofing.

After that, it depends on what is under the Duro-Last. Duro-Last website has the spec sheets for the product.

If you are a DYIer, if whatever you are using is listed as "fire retardant". Just ask you vendor for a copy of the fabric specs. On the spec sheet, it will clearly say what ratings the fabric has gone through.


The it's just a matter of adding the spec sheet to the other information you turn into the state code enforcement.

The other thing you can do is ask for a variance. This is a simple matter to do, most states you can file online.