Insulating Attic Joists

Standard joist spacing for the installation of attic flooring materials is 16 inches on center oc meaning the distance from the center of one joist to the center of the next joist is 16 inches.

Insulating attic joists.

1a attic access door. Although it s common to talk about installing insulation on the attic floor most attics don t really have a floor. More insulation installation tricks and tips work from the perimeter of the attic toward the door or hatch so that you don t trample all over the insulation you just. You can lay fiberglass sold in pre cut batts or rolls that you cut to size into the joist cavities or pour in loose fill insulation cellulose is the most common type although you can occasionally find glass fiber and rock wool.

If your insulation is just level with or below your floor joists i e you can easily see your joists you should add more. Either batting or blown insulation works in attics. Spread plastic sheeting over the crawlspace floor to block ground moisture from entering the area. In unfinished attic spaces insulate between and over the floor joists to seal off living spaces below.

No matter what kind of insulation you currently have in your attic one quick way to determine if you need more is to look across the span of your attic. When unrolled batting assumes its loft or thickness. Check the insulation manufacturer s instructions for the necessary thickness of plastic. Batting comes in rolls and is sized to fit between rafters or joists.

They have floor joists or the bottom chords of roof trusses with drywall below. In an unfinishedattic the most effective method is to add insulation between the joists of the attic floor. If the air distribution is in the attic space then consider insulating the rafters to move the distribution into the conditioned space. Fill the entire depth of the joists with insulation.

Overlap the seams by about 12 inches and run the plastic up the walls at least 6 inches. Always cover the tops of the ceiling joists to make sure the insulation is deep enough to reach your target r value and. Add new insulation if your attic has no insulation install either foil or kraft paper faced fiberglass rolls or batts in between all the attic floor joists which are also the ceiling joists of the rooms below.