Roxul ComfortBatt - Manual (Page 16)

16
Better | Best
Thermal insulation systems for
interior basement wall foundations.
Building codes are changing: R-values
are increasing
Insulating a new or unfinished basement is an
excellent way to make your home comfortable,
more energy efficient and reduce your overall
heating and cooling costs.
In addition to comfort and efficiency reasons for
insulating the basement, new building codes are
mandating that the foundation wall assembly have
increased R-values, depending on the climate
zone. Generally speaking, the colder the climate,
the higher the R-value requirements.
ROXUL ® has two thermal insulation products
for interior basement wall assemblies:
ROXUL COMFORTBOARd
™ IS (Insulation Sheathing)
and ROXUL COMFORTBATT ® . When used in tandem
within the 2 x 4 stud wall cavity, these two products
help create a drier, more comfortable basement.
Note: To help ensure soil moisture doesn’t have a
chance to seep through the concrete foundation, you
may wish to attach a layer of ROXUL dRAINBOARd
®
to the exposed exterior foundation before the soil
is filled in.
ROXUL dRAINBOARd is a rigid stone wool insulation
board specifically designed for foundation drainage.
Its non-directional fiber structure means the boards
can be installed either horizontally or vertically
without any loss of drainage performance.
Won’t trap moisture & won’t grow mold
or mildew
Basements are notorious for dampness, which
is why COMFORTBOARd
™ IS sheathing is so
highly recommended. Like all ROXUL insulations,
COMFORTBOARd IS is moisture-resistant and
yet vapor permeable: moisture can pass through
without being trapped.
COMFORTBOARd IS won’t absorb water and is not
susceptible to mold or mildew growth due to its
inorganic composition of basalt and recycled slag.
In the event of a basement leak where the insulation
becomes wet, COMFORTBOARd IS quickly dries out
and maintains its R-value.
COMFORTBOARD IS and the effects of
thermal bridging
Before recommending the Better
I
Best R-values for
the basement wall assembly, we need to understand
thermal bridging, the process that describes a material’s
capacity to conduct heat from one material to another.
In a typical basement, thermal energy transfers
from the interior of the concrete foundation through
the wood studs and eventually into soil to the exterior
of the foundation. The studs perform as the conduit
or “thermal bridge”, lowering the effective R-value
of the wall assembly. Insulated sheathing like
COMFORTBOARd IS reduces this thermal bridging
by acting as a thermal buffer between the concrete
and the studs.
Vapor Barrier or Not?
In many regions, particularly in colder climates, local building codes may require a vapor barrier within
the wall assembly. If so, remember to staple and overlap the vapor barrier to reduce reduce the rates of
vapor diffusion before adding the drywall. Note: The average below-grade temperature of soil is between
39.2-42.8 degrees Fahrenheit. Below 39 inches, the temperature remains constant all year round.