Attic insulation performs a critical role in residence energy performance. In reality, most building scientists agree that the attic must be the first “goal” space for insulation and air-sealing upgrades. Most properties are built with code-required minimum ranges of attic insulation which are far beneath present recommendations established by the U.S. Dept. of Energy.
Homeowners contemplating an attic insulation improve have a number of various insulation materials to consider. Every attic insulating possibility has distinct advantages and limitations. Understanding these execs and cons can assist you select the best insulation improve for your attic.
Fiberglass batt insulation is standard 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 ground joists, and unfaced batts are more common than confronted batts in attic installations.
PROS: Extra affordable than other sorts of attic cleaning and insulation cost insulation. Best sort of insulation for DIYers to install. In contrast to blown insulation, batts will be lifted up and moved to supply entry to the ceiling beneath, can lights and ceiling-mounted vent fans. Present batt insulation can often be left in place when blown insulation is added to extend total R-value within the attic.
CONS: Tough to put in accurately around obstructions. Voids where insulation is lacking contribute to important energy loss. Multiple layers of batt insulation are required to achieve recommended R-values in most parts of the country; this makes it unattainable to make use of the attic for storage except special platforms are constructed prior to insulation installation. Fiberglass insulation can’t cease air movement.
Two main forms of blown (or blow-in) insulation are generally used: cellulose and free-fill fiberglass. Both varieties are designed to be put in using special blowing equipment.
PROS: Set up might be accomplished quickly and affordably. Blown insulation typically results in extra complete 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 not possible to make use of the attic space for storage unless special platforms are constructed previous to installing the insulation. Cellulose and unfastened-fill fiberglass insulation cannot stop air movement.
Professional spray foam insulation contractors typically insulate an attic by applying a thick layer of spray foam between the rafters. Two forms of foam are used: open-cell and closed-cell. Opinions vary as to which type is best in an attic set up, but closed-cell spray foam is used more frequently.
PROS: Closed-cell spray foam provides the highest R-value 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 instead of on the attic ground frees up attic area for storage and different purposes. This strategy also improves the effectivity of HVAC components (like air handlers and ductwork) positioned in the attic.
CONS: Costliest attic insulation. A thick layer of foam applied to the underside of the roof sheathing can trap moisture and cause sheathing to rot.
Inflexible foam hasn’t been used as extensively for attic insulation until a most up-to-date development. In one unique system, a proprietary inflexible foam panel is fixed to the underside of attic rafters, forming an air and thermal barrier.
PROS: Offers all the benefits of spray foam, with the additional advantage of sustaining attic ventilation. The potential for roof sheathing moisture damage is eliminated. The inflexible foam is confronted with a radiant barrier that displays heat for additional energy savings -another advantage over spray foam.
CONS: The system is available in restricted areas, so it’s not as widely available as spray foam. Set up price is greater than fiberglass batts and blown insulation, however competitive with spray foam.