Page 33 - Green Builder Homeowner's Handbook 2016

Exteriors / Roofing / Structure / Insulation / IAQ / Windows / Heating / Lighting / Appliances / Faucets & Fixtures / Finishes / Cabinets & Tops / Alternative Energy

Cladding Considerations CREDIT: BUILDING SCIENCE CORPORATION Some claddings,
CREDIT: OWENS CORNING such as stucco
E XTRA-THICK LAYERS of exterior insulation can greatly and adhered
improve the energy performance of homes, but installation stone veneer, may
requires some special techniques. require additional
For thinner insulation, the cladding can often be attached directly support between
through the rigid insulation back to the structure. The practical limit the structural
of this approach is around 1-½” of rigid insulation, due to the limited furring strips
fastener lengths for many pneumatic nail guns. to facilitate the
For thicker insulation, vertical wood furring strips can provide installation. Wood
a cladding attachment location. This approach also provides a shingles require
drainage and ventilation gap behind the cladding, which helps a continuous nail
manage water. To adequately support the cladding, the furring strips base, which is
should be attached back to the structure using #10 or larger wood best provided by
screws that are sized to maintain a 1-¼” minimum embedment into installing another
the structural framing. layer of structural
sheathing directly
CELLULOSE over the insulation
Paper Trail in place of wood
Cellulose has a good green story to tell, especially from the furring strips.
manufacturing side. It’s made primarily with recycled paper, typically
newspapers, and most brands are treated with boric acid as a fire Fixing a Hole
retardant. Research on the health effects of boric acid suggest that with Attic Caps
it is a minor irritant in small doses. Cellulose can be installed wet
or dry. If installed wet, it should be allowed to dry properly before Easy-to-Use Options. Using a reflective material to cover
covering with drywall (typically less than 48 hours). The insulating stair openings, the Attic Stairways Insulator by Owens
value of cellulose is about the same as blown fiber glass (roughly Corning helps to reduce seasonal heat loss and gain.
R-3.7 per inch). While no one seems to have exact figures, third-party testing
MINERAL WOOL suggests that some brands cut attic air infiltration by 70 percent.
Nothing to Burn The ready-made systems, such as Owens Corning’s foil-covered
Although mineral wool looks like fiberglass, it’s made from basalt Attic Stairway Insulator (R-10; $54), are almost effortless to install.
rock and slag, not glass. The resulting product, either batts or loose Systems like those offered by Owens Corning work well in attics,
where traffic is infrequent. In homes where the homeowner
THE ARC HOUSE SPONSOR trucks in and out of the attic every day, however, other products
Bayseal Insulation offer more flexibility. For example, a rigid foam system such as
the Energy Guardian (R-38; $185) has a removable foam top.
Covestro’s Bayseal insulation provides a high R-value and reduces air The lightweight Attic Tent (R-3.2; $200) seals tightly with zippers.
intrusion, accumulation, radiative heat transfer and air movement. A So, how much energy do attic caps really save? Attic Tent
spray polyurethane foam expands, filling cracks, crevices and voids estimates about a 20 percent annual heating/cooling reduction.
to create a seamless air barrier system that provides high building The products also reduce unwanted air infiltration, offering other
envelope performance. http://bit.ly/2dM2Rty “green” benefits, such as keeping dust and pollutants out of living
areas and reducing drafts.
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The Homeowner’s Handbook 2016 GREEN BUILDER 31