Sustainable Building Technical Manual - Etn-presco.net

– Urethane foams are high-performance insulating materials available as rigid boardsor sprayed-in-place systems. These also were once made with CFCs and are nowmade with HCFCs.– Vermiculite and perlite are naturally occurring minerals that can be used in insulatingplaster mixes and in loose-fill applications such as filling cores of masonry walls.– A spray-in-place foamed silicate insulation made from sodium silicate and magnesiumoxychloride is available for use where fire retardancy and material safety arecritical. Used for cavity-fill applications and some surface uses, it is very moist whenapplied and can take several days to dry.– Reflective film-radiant insulation can be used effectively to reduce the radiant componentof energy transfer, such as excess heat gain from the sun. This material canbe particularly useful for reducing cooling loads in commercial buildings in sunnyclimates. It is made from aluminum foil and metallized plastics and usually installedin a roof cavity with an adjacent air space.❑ Health and pollution issues– Carefully handle and thoroughly clean up after using some thermal insulations,which may have health risks. It is recommended that they be applied in such a waythat they can be completely contained or isolated and cannot enter the building airhandlingsystem. Mineral fibers and glass fibers are now recognized by the UnitedStates government as possible carcinogens, and care should be taken by workers handlingthem. Cellulose fiber is relatively safe, but it contains borates and sulfates as fireretardants and stabilizers that are irritating and may require additional safety measures.The same is true for sprayable cellulose insulation containing mineral fiber.Vermiculite and perlite dust are potentially dangerous if inhaled, and should be handledwith caution. These natural mineral products should be certified as asbestos free.– Codes require a non-combustible covering over plastic insulations and may evenprohibit them in some uses. All plastic insulation materials release some gases suchas styrene and all are flammable, producing toxic gases when they burn. They areprimarily useful for exterior applications. Cutting with a hot wire releases toxicgases and should be avoided on building sites.Cladding and RoofingChoices of materials used in cladding and roofing are important for building longevity.The materials used for these purposes should be durable, recyclable, and appropriate forthe climate and application.❑ Resource-efficient options– Metal panels such as galvanized steel and enameled or anodized aluminum areappropriate for pitched roofs and cladding. They have the merit of using very littlematerial to cover the area, and they are durable and recyclable.– Composite shingles, tiles, and panels made from a variety of fiber-reinforcedcement products (some coated with plastics, enamels, or thin metals) are also availablefor pitched roofs and cladding. These are durable, and some contain recycledcontent. Although they are not recyclable, these are a good choice for durabilityand resource efficiency.– Stucco is a resource-efficient and durable finish where it is protected from moistureand frost damage by effective detailing. Acrylic-modified stucco is less massive andcan be installed on exterior insulation board, adding to thermal performance.– Where shingles are chosen for roofing, higher-quality asphalt shingles and fiberglassshingles are a moderately durable option. Some may be available with recycled content.– For flat roofs, torch-on roofing has important advantages. Also called “cold-processbuilt-up roofing,” it is fairly durable and repairable; although recycling systems arenot in place, this roofing is relatively easy to remove. Flat and shallow-pitched roofscan also be prepared with drainage mats and topsoil to grow grass, helping controlrainwater runoff and adding insulation value to the building, while also providinghabitat for birds and other wildlife.