What Is the Proper Way to Insulate an Attic?

Methods

• Attic insulation installers may lay down solid batting or employ blown-in materials in covering attic surfaces. Large, regular areas near the attic joists can receive solid slabs of insulation batting called blanket rolls, while machines that blow loose-fill insulation can cover irregular areas or cavities.

Materials

• Loose-fill insulation may include fiberglass, mineral wool or cellulose. Fiberglass contains thousands of tiny glass fibers, mineral wool consists of recycled industrial slag or natural minerals, and cellulose uses recycled newsprint. Batting consists of fiberglass, mineral wool, natural fibers or plastic fibers.

Considerations

• Adding extra insulation can improve the performance of existing insulation. If the existing insulation has few or no gaps in it, installers can press new batting into place next to the older materials, according to This Old House. Gaps in the existing insulation may require filling in with blown-in loose-fill insulation.