10 -024 classic-max-cover-letter-to-code-officials
6747 Campobello Road, Mississauga, ON, Canada L5N 2L7
Toll Free: 800.758.7325 Fax: 905.363.0102 www.Icynene.com
To Whom It May Concern:
Icynene Classic Max™ (LD-C-50v2) has been approved for use without an ignition barrier in all
residential applications. The addition of the unvented attic was approved following extensive
research and consultation by Icynene with the ICC-ES to ensure all testing met the strict safety
guidelines and standards mandated by ICC-ES. The ESR report 1826 was amended with the
following:
4.4.2.2 Attics – LD-C-50 v2: When LD-C-50 v2 is applied in unvented attics conforming to 2012
IRC Section R806.5 or 2009 IRC Section R806.4, the insulation may be applied to the underside
of roof sheathing and/or rafters to a minimum thickness of 51/2 inches (140 mm) and a minimum
thickness of 11/2 inches (38 mm) over the rafters; and may be applied to vertical wall surfaces to
a minimum thickness of 51/2 inches (140 mm) and a minimum thickness of 11/2 inches (38 mm)
over the studs. Maximum thickness on the underside of roof sheathing or on vertical wall
surfaces is 20 inches (508 mm). The insulation may be left exposed to the attic without a
prescriptive ignition barrier or an intumescent coating.
Unvented attics conforming to this design requirement will be identified with an Icynene
insulation certificate posted in the attic.
Please contact me at 1-800-758-7325 ext. 209 or visit our website www.icynene.com for more
information.
Regards,
Paul Duffy
VP Engineering, Icynene