Attic insulation performs a important role in dwelling energy performance. In reality, most building scientists agree that the attic must be the primary “goal” space for insulation and air-sealing upgrades. Most homes are constructed with code-required minimum levels of attic insulation which can be far below current recommendations established by the U.S. Dept. of Energy.
Homeowners contemplating an attic insulation improve have a number of various insulation materials to consider. Each attic insulating possibility has distinct benefits and limitations. Understanding these pros and cons can assist you choose the best insulation improve in your attic.
Fiberglass batt insulation is in style because it is 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 more widespread than confronted batts in attic installations.
PROS: Extra affordable than different forms of attic insulation. Finest kind of insulation for DIYers to install. Unlike blown insulation, batts might be lifted up and moved to offer access to the ceiling beneath, can lights and ceiling-mounted vent fans. Current batt insulation can typically be left in place when blown insulation is added to extend total R-value in the attic.
CONS: Troublesome to install accurately round obstructions. Voids the place insulation is missing contribute to important energy loss. Multiple layers of batt insulation are required to realize really helpful R-values in most components of the nation; this makes it not possible to use the attic for storage unless special platforms are built prior to insulation installation. Fiberglass insulation cannot cease air movement.
Two essential types of blown (or blow-in) insulation are commonly used: cellulose and free-fill fiberglass. Both varieties are designed to be put in using particular blowing equipment.
PROS: Installation may be accomplished rapidly and affordably. Blown insulation typically leads to more full coverage than is feasible with fiberglass batts.
CONS: A thick layer of insulation (a minimum of 16 in. for northern parts of the U.S.) is required, and this makes it inconceivable to make use of the attic space for storage unless particular platforms are constructed prior to putting in the insulation installation alamo. Cellulose and loose-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 varieties of foam are used: open-cell and closed-cell. Opinions fluctuate as to which sort is finest in an attic installation, however closed-cell spray foam is used more frequently.
PROS: Closed-cell spray foam offers the very 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 flooring frees up attic space for storage and different purposes. This strategy additionally improves the efficiency of HVAC elements (like air handlers and ductwork) located within the attic.
CONS: Most expensive attic insulation. A thick layer of foam 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 until a most recent development. In one unique system, a proprietary rigid foam panel is fixed to the underside of attic rafters, forming an air and thermal barrier.
PROS: Gives all the advantages of spray foam, with the extra advantage of maintaining 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 extensively available as spray foam. Set up price is greater than fiberglass batts and blown insulation, however aggressive with spray foam.