20080811132702.pdff10c.1890
CITY OF EDMONDS
121 5TH AVENUE NORTH • EDMONDS, WA 98020 • (425) 771-0220 • FAX (425) 771-0221
Website: www.ai.edm0nd8.wa.us
DEVELOPMENT SERVICES DEPARTMENT
Planning • Building • Engineering
August 11, 2008
Shaun Leiser
SCL Enterprises
P.O. Box 60216
Shoreline, WA98160
RE: Use of Icynene Insulation System at 303 Walnut Street, Edmonds
Dear Mr. Leiser:
GARY HAAKENSON
MAYOR
The Office of the City Building Official is in receipt of your request for Alternate Materials
Method of Construction, Design or Insulating Systems as set forth in WSEC 103 to use Icynene
Insulation System for roof insulation.
Section 502.1.4.3 of the 2006 Washington State Energy Code requires ventilation between the top
of the insulation and roof deck. Icynene Insulation System is installed directly to the underside of
the roof deck without this air space.
The 2004 Supplement to the International Residential code and draft 2007 Supplement to the IRC
support the installation of air impermeable insulation to be applied directly to the underside of the
roof deck. Icynene Insulation System is air impermeable (ASTM E283 with less than 0.02 L/S-
mz). Product has also been evaluated by ICC in report NER-420.
After review of all of the information provided, it is my determination as Building Official for the
City of Edmonds that the use of Icynene Insulation System is approved as an Alternate Materials
Methods of Insulating Systems for roof insulation under the provisions of WSEC 103 at 303
Walnut Street, Edmonds with the following conditions:
• The product must be installed in accordance with the manufacturer's installation
instructions.
• The unvented attic space is completely contained within the building thermal envelope.
• No interior vapor retarders are installed on the ceiling side of the unvented attic
assembly.
Sincerely,
%4-,
Ann Bullis, CBO
Building Official
• Incorporated August 11, 1890 •
Sister City - Hekinan, Japan