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CrossLam Cross Laminated Timber

CrossLam is a cross-laminated timber (CLT) structural panel made by gluing layers of softwood boards one on top of the next at right angles to each other… Read more
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  • Just how low the VOC level needs to be for a given product to qualify for inclusion in GreenSpec depends on the product category. For most products, we require certification to California’s health-based emissions standard, CDPH Std Method v1.1 standard (also referred to as California Section 01350), which tests a product’s resultant VOC concentrations in the space after a given period of time. For wet-applied products like paints, caulks, and adhesives, we still also look for VOC content instead of, or in addition to, verified low emissions; this is because emissions testing doesn’t adequately test initial offgassing, and VOC content is currently the only widely available proxy.

Brent Ehrlich
Products Editor

CrossLam is a cross-laminated timber (CLT) structural panel made by gluing layers of softwood boards one on top of the next at right angles to each other. The resulting panels are light and dimensionally stable in all directions and can be used for floors, walls, and roofing. CLT is made from less desirable wood, including wood taken from forests killed by mountain pine beetles, but higher quality wood can be used if it is going to be exposed to view, and FSC-certified wood is available. CLT comes in panels up to 40 feet long, 10 feet wide, and 12 inches thick and uses formaldehyde-free Purebond polyurethane adhesive.

Engineered timber products can provide a significant environmental advantage over solid wood and other building materials: they efficiently utilize fast-growing, small-diameter trees; in responsibly managed forests they sequester carbon that would otherwise enter the atmosphere; they provide a connection to nature when left exposed on building interiors; and they can even provide a viable replacement for energy-intensive steel and concrete in some structural applications.

For decades, engineered timber has been made with exterior-grade, no-added-urea-formaldehyde (NAUF) resins, including phenol formaldehyde, melamine formaldehyde, resourcinol formaldehyde, or phenol-resourcinol formaldehyde. Similar to exterior sheathing, which also uses phenol formaldehyde, engineered timber is exempt from CARB emissions testing because of low emissions, but engineered lumber products are now available with formaldehyde-free polyurethane resins.

Products listed in GreenSpec contain no-added formaldehyde resins, are available with FSC-certified content, or offer other environmental benefits.

LEED Credits

EQc4.3: Low-Emitting Materials—Carpet Systems

EQc4.4: Low-Emitting Materials—Composite Wood&Agrifiber Products

IEQc4.3: Low-Emitting Materials—Flooring Systems

IEQc4.4: Low-Emitting Materials—Composite Wood and Agrifiber Products

MRc6: Certified Wood

MRc7: Certified Wood

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