A
major difference in building codes for residential versus
commercial building involves combustible components.
For the most part, residential construction is not restrictive
in materials used. Commercial buildings, specifically Type
I-IV of the International Building Code, restrict the use of
combustible components in exterior walls. This includes air barriers,
combustible cladding, and foam plastic insulation. Fortunately for
manufacturers of these materials, the code provides a path for
establishing compliance to the non-combustible intent, via testing per
"NFPA 285, Standard Fire Test for Evaluation of Fire Propogation
Characteristics of Exterior Non-Load-Bearing Assemblies Containing
Combustible Components".
NFPA 285 is a duanting fire assembly test. Roughly, a 14' wide by 30'
tall wall is assembled, complete with base wall such as steel stud with
interior and exterior gypsum sheathing, exterior air barriers, flashing,
insulation, wall ties, and exterior cladding such as brick. A 6' wide
window opening (no glass) in the lower part of the wall is flashed and
fire blocked per actual field conditions. The test simulates a fire occuring
inside the building by positioning a large burner at the window from the
inside. After 5 minutes, another large burner is added to the exterior of
the window. Every 5 minutes after, until 30 minutes, the gas flow to the
burners is increased.
Many commercial air barriers, common foam plastics, and combustible
claddings have been tested via NFPA 285. EPS-IA members with an
Fire Code
Approval for EPS in
Commercial Walls
interest in serving the exterior commercial wall segment commissioned
testing at Intertek to assess EPS for NFPA 285 approval. The assembly
chosen for the test emphasized high fuel content components and
marginal fire protection elements to simulate a higher fire risk than
would ever typically be encountered in the built world. The resulting test
report validated approval of EPS in wall assemblies with cementitious
claddings such as brick, natural stone or stucco.
The International Building Code requires that foam products sold for use
in commercial walls bear the mark of an approved agency to validate the
NFPA 285 and other associated approvals. EPS-IA members who have
participated in the NFPA 285 program can be found listed in approved
product directories such as Underwriters Laboratories Certification
Directory, Intertek Warnock Hersey Directory, ICC-ES Evaluation Reports,
etc.
Addition of EPS foam products to NFPA 285 approved wall assemblies
provide architects with another option for meeting ASHREA 90.1 and
IECC continuous insulation requirements. EPS offers stable R-value that
increases as temperatures decline, closed cells that only contain air,
vapor permeance higher than other foam plastics and availability from
local manufacturers to reduce transit emissions.
For more information contact EpS-IA
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