Dow THERMAX™ OR STYROFOAM™ - Manual

the closed crawl space is gaining popularity
for its effectiveness in reducing energy loss
and minimizing the potential for moisture
problems. dow offers the following guidelines
for constructing a closed crawl space with an
insulation system that includes thermaX™ or
styrofoam™ brand rigid insulation on interior
crawl space walls, a continuous poly vapor barrier
to prevent evaporation of ground moisture into
the crawl space, and a means to condition the
crawl space to keep the relative humidity below
70 percent to mitigate mold and mildew growth.
(see figure 1.)
About THERMAX™
Rigid Insulation
thermaX™ rigid insulation boards have a glass-
fiber-reinforced polyisocyanurate foam core,
with special laminated aluminum facers that
enhance moisture and damage resistance. this
reinforcement is chemically modified to provide
improved fire performance. thermaX rigid
insulation boards can be left exposed in crawl
spaces per national evaluation services report
ner-681. thermaX rigid insulation boards are
also factory mutual approved as a “wall-ceiling
construction, fm approvals standard fm 4880,
metal-faced – class 1 fire rated to a max, 30
ft. high.” consult the local building codes in your
area before starting construction.
About STYROFOAM™ Brand
Rigid Insulation
styrofoam™ brand rigid insulation boards are
made from extruded polystyrene foam insulation
and have exceptional water resistance, long-
term thermal performance and high compressive
strength. astm c578 type X and astm
c578 type iV styrofoam Brand extruded
polystyrene foam insulation boards, with a
maximum nominal thickness of 2 inches (51mm),
may be installed on surfaces (wall, ceiling) of a
crawl space with no coverings (no thermal or
ignition barrier) applied to the crawl space side of
the foam plastic insulation per international code
council evaluation service (icc-es) evaluation
report esr-2142.
Figure 1
Closed Crawl Space
Please note that closed crawl spaces may include
components not shown, such as other ventilation
options, floor drains, radon mitigation, etc.
United states . installation information . residential
INSTALLATION PROCEDURES FOR
THERMAX™ OR STYROFOAM™
BRAND RIGID INSULATION