Attic insulation plays a crucial function in home energy performance. In reality, most building scientists agree that the attic ought to be the first “target” area for insulation and air-sealing upgrades. Most houses are constructed with code-required minimal levels of attic insulation which are far beneath current recommendations established by the U.S. Dept. of Energy.
Householders considering an attic insulation improve have a number of various insulation materials to consider. Each attic insulating possibility has distinct advantages and limitations. Understanding these pros and cons can help you select the most effective insulation improve on your attic.
Fiberglass batt insulation is fashionable because it’s affordable and universally available. Regardless of age, many houses have attics insulated with fiberglass batts. The batts are typically put in between attic floor joists, and unfaced batts are extra common than faced batts in attic installations.
PROS: Extra affordable than other forms of attic insulation. Greatest kind of insulation for DIYers to install. Not like blown insulation, batts could be lifted up and moved to offer access to the ceiling beneath, can lights and ceiling-mounted vent fans. Existing batt insulation can typically be left in place when blown insulation is added to increase total R-worth in the attic.
CONS: Difficult to install accurately around obstructions. Voids the place insulation is lacking contribute to important energy loss. A number of layers of batt insulation are required to attain advisable R-values in most components of the nation; this makes it inconceivable to use the attic for storage until special platforms are constructed previous to insulation installation. Fiberglass insulation cannot cease air movement.
Two primary forms of blown (or blow-in) insulation are generally used: cellulose and free-fill fiberglass. Each types are designed to be installed using particular blowing equipment.
PROS: Set up might be accomplished rapidly and affordably. Blown insulation typically ends in more full coverage than is possible with fiberglass batts.
CONS: A thick layer of insulation (at least sixteen in. for northern elements of the U.S.) is required, and this makes it inconceivable to use the attic area for storage unless special platforms are constructed previous to putting in the insulation. Cellulose and free-fill fiberglass insulation can’t stop air movement.
Professional spray foam insulation contractors typically insulate an attic by making use of a thick layer of spray foam between the rafters. Two types of foam are used: open-cell and closed-cell. Opinions differ as to which type is best in an attic installation, but closed-cell spray foam is used extra frequently.
PROS: Closed-cell spray foam offers the highest R-worth per in. (about R-6) of any attic insulation. It also 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 house for storage and different purposes. This strategy additionally improves the efficiency of HVAC parts (like air handlers and ductwork) situated in the attic.
CONS: Costliest attic insulation installation alamo. A thick layer of froth utilized 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 one distinctive system, a proprietary rigid foam panel is fastened to the underside of attic rafters, forming an air and thermal barrier.
PROS: Supplies all the benefits of spray foam, with the extra good thing about maintaining 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 financial savings -another benefit over spray foam.
CONS: The system is available in restricted areas, so it isn’t as widely available as spray foam. Set up cost is larger than fiberglass batts and blown insulation, however competitive with spray foam.