Sustainable Building Technical Manual - Etn-presco.net

❑ Resource-efficient options– Determine whether domestic wood is produced through sustainable forest management.Although this can be difficult, ASTM is developing a sustainably harvestedwood standard that can be specified in building construction. An increasing numberof producers have sustainable-based management programs and participate in thirdpartycertification programs.– Low-grade fiber, small-diameter trees, and fast-growing, less-utilized tree species canbe used in engineered wood products and value-added products such as “I” joists,oriented strand board, laminated veneer lumber, finger-jointed lumber, open-webwood joists and trusses, stressed skin wood panels, and wood/steel joists. Salvagedtimber and wood products are available from operators who disassemble old buildingsand bridges and then clean, grade, and often resaw the timber.– Structural sheathing made from pressed post-consumer newsprint is also available.This material not only uses a recycled material but also adds substantial insulatingvalue and acoustic absorption to the wall or roof. In some circumstances, nonstructuralinsulating sheathing such as wood-fiber or glass-fiber boards can also be usedwith steel-strap and bracket-shear braces.❑ Health and pollution issues– Indoor-air-pollution emissions from glues used in the manufacturing process of someengineered wood products are substantial.– Those made with exterior-type glues (phenolic resins) and urethane (polyurea) adhesiveshave some of the lowest emissions.7Division 7:Thermal Insulation and MoistureProtectionInsulationThermal insulation can be an important factor in the energy performance of commercialbuildings, depending on the climate, building form and orientation, occupancy, and use.Achieving high insulation values by designing larger cavities or using higher-performancematerials may be cost-effective. Once the desired insulation value has been determined, amaterial can be selected that is resource efficient and that addresses health issues.❑ Resource-efficient options– Mineral-fiber insulation is made primarily from basalt rock or steel mill slag. It is availablein loose-fill form, batts, and rigid boards, and can be used for most applications.– Glass-fiber insulation is now available with 30 percent or more post-consumer recycledglass content from cullet. 8 It is available in loose-fill form, batts, and rigid boards.– Cellulose thermal insulation and acoustic sprayed coatings contain at least 70 percentpost-consumer paper waste. These are available only in loose-fill form. Wallscan be insulated using the “blown-in batt” system, installed with a high-pressureblower and containment screen. If installed to density specifications, the insulationdoes not settle after application. Horizontal spaces are filled with a low-pressureblower. Some systems use a small amount of moisture to encourage stabilization.Sprayed cellulose systems are designed for acoustic and fire retardancy and may containmineral fiber.– Foamed polystyrene insulation is available with post-consumer recycled contentfrom recycled fast-food containers and hot drink cups. “Expanded” types are madewith a steam process and a non-chlorofluorocarbon (CFC) gas. “Extruded” types,which offer higher performance, were previously made with CFCs. However, they arenow made with hydrochlorofluorocarbons (HCFCs), which have far less ozonedepletingpotential. New extruded products containing no HCFCs will soon becomeavailable, although they contain chemicals that are now being evaluated based ontheir global warming potential.