Below is the "Weather
Barrier Statement," from the VSI, and the real impetus
for the big push toward the latest house-wrap mentality.
The Vinyl Siding Institute
issued: "The VSI Weather Resistant Barrier Statement."
The Vinyl Siding Institute (VSI) is the trade association
representing manufacturers of vinyl siding as well as suppliers
of raw materials, equipment, and services to the industry.
NEW CODE V.S.I.
2003- 2004 Vinyl siding provides
a supplemental rain screen that enhances the
weather-resistant exterior wall system by reducing the amount
of water that reaches the underlying weather-resistant barrier.
Because of its design and application, vinyl siding allows
the material underneath it to breathe, helping to keep the
structure of the home or building safer and healthier. A weather-resistant
exterior wall system is defined as a system that includes
water shedding materials and water diversion materials. The
exterior wall system commonly consist of a combination of
exterior cladding such as vinyl siding, flashed wall openings
and penetrations, weather resistant barrier material, and
sheathing. Effective exterior wall systems will shed the water
initially, control moisture flow by capillary and diffusion
action, and minimize absorption into the wall structure. The
weather resistance requirement is determined by the applicable
building code and climate. Requirement: 2004 International
Residential Code (IRC) Supplement To achieve designed performance
and to comply with the IRC, vinyl siding must be installed
over a weather resistant barrier system that includes both:
continuous weather resistant material complying with ASTM
D226 or other approved weather-resistant material, and
properly integrated flashing around all penetrations where
vinyl siding interfaces with other building products such
as brick, stone, or stucco. Refer to VSI's “Vinyl Siding
Installation Manual” (www.vinylsiding.org/install/guide.pdf)
which is based in part on ASTM D4756, Standard Practice for
Installation of Rigid Poly (Vinyl Chloride) (PVC) Siding and
Soffit or the manufacturer's installation manual for specific
product applications and recommendations.
used as part of a weather-resistant exterior wall system should
meet the applicable code. Contact the manufacturer of the
weather resistant barrier material(s) to ask about building
codes. Always consult the applicable building code for minimum
weather barrier requirements in a given area. Note that additional
measures may provide increased protection against water intrusion
than the minimum requirements of the building code. For more
information visit www.vinylsiding.org or call Kisha Riddick
at VSI at (202) 587-5106. The Vinyl Siding Institute, Inc.,
is located at the National Housing Center in Washington, DC,
and represents manufacturers of vinyl siding and suppliers
to the vinyl siding industry.