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.

If the air distribution is in the attic space then consider insulating the rafters to move the distribution into the conditioned space. They have floor joists or the bottom chords of roof trusses with drywall below. So insulating the floor of the attic is not only the best solution but it is also the simplest and cheapest. Batting comes in rolls and is sized to fit between rafters or joists.

In unfinished attic spaces insulate between and over the floor joists to seal off living spaces below. 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. Either batting or blown insulation works in attics. In practical terms you can choose between mineral wool or insulation boards.

Spread plastic sheeting over the crawlspace floor to block ground moisture from entering the area. Check the insulation manufacturer s instructions for the necessary thickness of plastic. 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. In an unfinishedattic the most effective method is to add insulation between the joists of the attic floor.

Although it s common to talk about installing insulation on the attic floor most attics don t really have a floor. When unrolled batting assumes its loft or thickness. 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. 1a attic access door.

Always cover the tops of the ceiling joists to make sure the insulation is deep enough to reach your target r value and. 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. If your insulation is just level with or below your floor joists i e you can easily see your joists you should add more.