Interpretation #7509
Published June 15, 2015
Original Request
- Code Version
- 2014
- Code
- BUILDING
- Code Description
- Chapter
- Section
- 706.4.1
- Topic
- Intumescent Coating for Fire Resistance
Question
I would like to use a fire retardant paint to treat the plywood on the 4 foot underside of the roof to meet the fire resistance requirement on each side of the exterior dividing wall. Will this comply with the code requirement?
Answer Published 06/15/2015 at 8:41 AM
No. Please see the attached commentary for additional
information.
information.
Commentary
The code requires fire retardant treated wood. Treated wood
is defined as - "wood and wood based materials that use
vacuum-pressure impregnation processes to enhance fire
retardant or preservative properties." According to the code,
painting an intumescent coating on a piece of plywood would
not meet the strict definition of treated wood, the building
official should be careful if accepting this using 104.11.