Attic insulation plays a essential position in dwelling energy performance. In fact, most building scientists agree that the attic needs to be the primary “target” space for insulation and air-sealing upgrades. Most houses are constructed with code-required minimum levels of attic insulation which might be far under present suggestions established by the U.S. Dept. of Energy.
Owners contemplating an attic insulation upgrade have a number of different insulation materials to consider. Every attic insulating possibility has distinct advantages and limitations. Understanding these pros and cons might help you select the very best insulation improve to your attic.
Fiberglass batt insulation is standard because it is affordable and universally available. Regardless of age, many houses have attics insulated with fiberglass batts. The batts are typically installed between attic ground joists, and unfaced batts are extra frequent than faced batts in attic installations.
PROS: Extra affordable than different kinds of attic insulation. Best type of insulation for DIYers to install. Unlike blown insulation, batts may be lifted up and moved to offer entry to the ceiling beneath, can lights and ceiling-mounted vent fans. Present batt insulation can usually be left in place when blown insulation is added to extend overall R-value in the attic.
CONS: Troublesome to put in correctly round obstructions. Voids where insulation is lacking contribute to significant energy loss. A number of layers of batt insulation are required to realize really useful R-values in most parts of the country; this makes it inconceivable to use the attic for storage unless special platforms are constructed prior to insulation installation. Fiberglass insulation cannot cease air movement.
Two primary forms of blown (or blow-in) insulation are generally used: cellulose and unfastened-fill fiberglass. Each sorts are designed to be installed utilizing particular blowing equipment.
PROS: Installation could be completed quickly and affordably. Blown insulation typically leads to extra full protection than is possible with fiberglass batts.
CONS: A thick layer of insulation (not less than sixteen in. for northern parts of the U.S.) is required, and this makes it impossible to make use of the attic space for storage except special platforms are built prior to installing the insulation installation alamo. Cellulose and free-fill fiberglass insulation can’t cease air movement.
Skilled spray foam insulation contractors typically insulate an attic by applying a thick layer of spray foam between the rafters. Two types of foam are used: open-cell and closed-cell. Opinions vary as to which kind is finest in an attic installation, however closed-cell spray foam is used extra frequently.
PROS: Closed-cell spray foam offers the best R-worth per in. (about R-6) of any attic insulation. It additionally creates an air and moisture barrier, so it eliminates the need for separate air-sealing work. Insulating beneath the roof deck as a substitute of on the attic floor frees up attic area for storage and other purposes. This technique also improves the effectivity of HVAC components (like air handlers and ductwork) situated within the attic.
CONS: Costliest attic insulation. A thick layer of foam applied to the underside of the roof sheathing can lure moisture and cause sheathing to rot.
Rigid foam hasn’t been used as extensively for attic insulation till a most up-to-date development. In a single distinctive system, a proprietary inflexible foam panel is fastened to the underside of attic rafters, forming an air and thermal barrier.
PROS: Offers all the benefits of spray foam, with the additional benefit of sustaining attic ventilation. The potential for roof sheathing moisture damage is eliminated. The inflexible foam is faced with a radiant barrier that reflects heat for added energy savings -another advantage over spray foam.
CONS: The system is available in restricted areas, so it’s not as extensively available as spray foam. Installation cost is greater than fiberglass batts and blown insulation, however competitive with spray foam.