INSTALLING INSULATION ROLLS
Roll insulation can be used anywhere in your home, although they are best for covering long unobstructed areas like attics and crawl spaces.
Roll insulation can be cut to fit any size cavity and are typically available in faced and unfaced. There is insulation you can purchase which is poly-encapsulated, or wrapped in plastic, for a more comfortable installation with less itch and dust. The plastic facing also serves as a vapor retarder.
Faced insulation is used in exterior walls as well as attics, finished basements, ceilings, floors, knee walls and cathedral ceilings. Like other forms of insulation, rolls are available in a variety of R-values.
When choosing roll insulation, make sure you use the most appropriate R-value.
How to Install Roll Insulation
To open packages cut lengthwise through the side panel. Be careful to avoid cutting the product or facing. Insulation will quickly expand to its full volume when the bag is opened.
Push batts gently into the cavity so that it sits all the way in, especially check that the corners and edges are in. Then fluff it to its full expansion by pulling it forward to fill the depth of the cavity. It should fit snugly.
With batts that have facing on them, make sure the facing is toward the conditioned interior space, unless the building codes state differently.
Let friction hold the batts in place, or you can staple the flanges of faced batts to the inside or the face of the joists. Stapling on the inside is best because it is easier for drywallers and the drywall has a more even fit. Sometimes, however, the local building codes may require you to overlap the flanges and staple them to the edges of the framing members.
Be careful not to stretch the facing too tight as you staple. This can over-compress the batt and avoids gaps and puckers.
Secure floor insulation with wire fasteners (sometimes called "lightning rods"). Press the fasteners so they bow up gently against the subflooring without compressing it. Space them at least 6" from each end of the batt and 12" to 24" apart.
Cut insulation about an inch wider than the space using a sharp utility knife against a safe backstop, such as an unfinished floor or other smooth, flat surface. Always cut on the unfaced side of the batt. Sometimes batts have vertical perforations at intervals along the width of the batt so cutting is not needed. Simply grip the insulation on either side of the perforations and tear to trim it to the desired width.
If spaces are shorter, you will have to cut the insulation to fit properly. Never double it over or compress it because that will change the R-value of the insulation.
If it takes more than one batt to fill a cavity, be sure the two pieces are butted snugly together.