Page 54 - October 2015 Green Builder Magazine

Product Spotlight: Insulation and Air Sealing

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to use, as long as “the decisions to use it compare products of Naturally Renewable. Thermacork’s rigid cork insulation comes
equivalent performance.”
in several thicknesses and averages R-4 per inch. The company
Cork holds a similar position as mineral wool, being a 100
percent natural material with superior thermal and acoustic also makes a denser exterior cork cladding product.
insulating qualities—but it’s certainly not locally sourced, unless www.thermacork.com
you’re building a house in Portugal. ThermaCork offers expanded
cork insulation panels that can be used rigid insulation, replacing
exterior rigid foam like EPS or XPS. The company claims that
because cork trees are carbon sinks (harvesting cork does not
damage the trees), and that when the harvesting and manufacturing
processes and benefits to the local economies in which the cork
is harvested are taken into account, cork insulation is actually a
carbon-negative product.

Although costs of high-performance and sustainable products
tend to decrease over time, cork insulation panels, like semi-rigid
mineral-wool panels, will be initially more expensive than other
similar plastic or petroleum-based products.

Most recently, there’s been some hype surrounding wood foam

www.greenbuildermedia.com 10.2015 Outside Job
INCORPORATING ONE OR more layers of exterior
rigid insulation can significantly add to the energy
performance of a building. These layers don’t just
add R-value; they create a thermal break between
the building envelope and the external environment. This
is significant, as the wood framing members in a typical
wood-framed house can reduce cavity insulation’s nominal
insulation value by 15 to 20 percent. In other words, exterior
insulation performs very close to its stated R-value.

R-VALUES FOR SOME COMMON EXTERIOR 6.5 Multiple Benefits. DuPont Tyvek
INSULATION PRODUCTS: 5.0 ThermaWrap R5.0 offers the air and
4.0 water management benefits
Foil-Faced Polyisocyanueate 4.0 of DuPont Tyvek HomeWrap and
Extruded Polystyrene (XPS) adds R-5 to the wall assembly.
Expanded Polystyrene (EPS) www.dupont.com
Rigid Mineral Fiber
Another variation on exterior insulation is DuPont’s Tyvek
Another advantage of exterior rigid insulation is that it ThermaWrap R5.0, a housewrap that provides an insulating
provides moisture management by keeping the exterior value of R-5. Unlike other exterior insulation products,
sheathing warmer. This reduces the chance of condensation, ThermaWrap is breathable. The company claims this is an
especially in colder climates; in fact, the vapor barrier can be advantage, as it allows any moisture that finds its way into the
eliminated if the R-value of the rigid insulation is sufficient. wall cavity to escape.
This value varies with the framing method (2’ x 4’ vs. 2’ x 6’)
and climate zone. Source: http://1.usa.gov/1IbBKhU