Polyiso Foam Roof Insulation:
It’s More than R-value, It’s Meeting the Codes
Alexandria, VA – The demands on roof insulation in a modern roofing system go beyond R-value. Today, roof insulation also
must deliver:
• High insulation efficiency and value
• Superior physical properties to meet the requirements of the architect or specifier
• The performance expected by roofing contractors
• A long and trouble free service life for the building owner
• Compliance with building code and insurance regulations to ensure certified fire and wind resistance in the
completed roofing system
For decades, polyiso roof insulation has met all these
requirements and, as a result, is now the most popular foam plastic
roof insulation specified and used in new and re-roofing projects. Production
of polyiso in 2004 exceeded 5.4 billion board feet.
As the building industry continues to
strive for more efficient buildings, the
demands from contractors, designers and building owners for highly energy-efficient
polyiso insulation are driving a very strong market. However, core raw
material costs are rising dramatically for all manufacturers, and in
some cases chemical availability is impacted.
As a result, some specifiers
and installers are considering the use of
other roof insulation products to replace polyiso. Be
sure that the alternate roof insulation meets building
code requirements for fire and wind ratings, or specifications which
require performance above and beyond the minimums described in the local
building code – such as a requirement that the system be “FM
(Factory Mutual) Approved.”
Polyiso roof insulation is the only foam plastic roof
insulation board product that meets the strict standards of both FM Approvals
(Standard 4450) and UL (UL1256) without the use of an additional thermal
barrier layer between the insulation and the supporting steel roof deck.
In the past some assemblies with polystyrene insulation gained FM Approvals
but only when a properly designed sprinkler system was installed in
the building with the rated roofing system. FM Approvals no longer approve
roof assemblies which require automatic sprinklers in order to meet
fire spread requirements. Currently, all FM Approvals using polystyrene
roof insulation on a steel deck require a thermal barrier under the
foam.
Additionally, strictly adhere to the “Limitation of Use” when using ICBO, SBCCI, BOCA or ICC Evaluation
Reports as a demonstration of code compliance for these alternate foam roof insulations. The product must be
installed as tested and some polystyrene evaluation reports may list a prohibition against re-roofing or may
require automatic sprinklers in the building.
To ensure compliance with the most demanding building
code and insurance safety requirements, use the most versatile and cost-effective
product available today—polyiso roof insulation. As always, check with your
polyiso supplier frequently to stay current with market developments and order materials as early in the contract
process as possible. No other insulation product performs like polyiso, and your efforts to use of the best
available high-performance thermal product will contribute to the long term, sustainable performance of your
roofing project.
PIMA is the national trade organization that advances
the use of polyiso insulation, one of the most widely used and cost-effective
insulation products. PIMA’s membership consists of manufacturers and marketers of polyiso
insulation, as well as suppliers to the industry. For updates on this topic,
please visit the PIMA Web site at www.PIMA.org, or call 301-654-0000.
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