Wall insulation requirements vary for different regions of the country according to building codes. The purpose of the insulation is to manage thermal (hot and cold) transmission through a wall assembly. It should be installed in accordance with the manufacturer’s recommendations to best serve its purpose. Wall insulation is generally provided in batts, rolls, sheets, or loose packaging. Common types of wall insulation in residential construction are:
Unfaced Fiberglass Batt or Rolls
This type of insulation is made from fine, thin layers of fiberglass, loosely woven together, creating a “blanket” of insulation fibers. Air pockets are developed in the process. These air pockets serve to trap air between the fibers. The fiberglass is woven in various thickness to fill the cavity between the framing in the wall of your house. Batt insulation is prepared in pre-measured, usually rectangular pieces that are stacked together for purchase. Rolls of fiberglass insulation are pre-measured in width and height to fit between the studs in the walls of your house and come prepared in rolls for purchase. Installation of this product is amazingly simple – lift and place!
Faced Fiberglass Batt or Rolls
Faced fiberglass insulation is like the unfaced fiberglass insulation except there is a layer of paper (called facing) on one side of the insulation. This paper facing is a vapor retarder (not to be confused with a vapor barrier) which serves to slow the process of vapor travel through the wall of your house. With this product, care should be extended as to which side of the wall the facing is installed. Due to climate, different regions of the country require the facing to be installed on certain sides of the wall. Review the manufacturer’s guidance for proper installation directions.
Cellulose insulation is a wood-based product usually made from recycled paper, something like newspaper or cardboard. It is loosely installed creating air gaps in the layer of insulation. The insulation is chemically treated to resist fungal growth (mold) and fire. This product is white to light grey in color and is generally installed by blowing the insulation into place by mechanical means.
Mineral wood is typically made for basalt (volcanic rock) and/or slag (industrial waste). This inorganic product is melted and spun making small fibers that are woven together creating a blanket of fibers with air pockets. The final product is produced in batts to fit between wall studs and is denser that fiberglass batts. It can be cut to precise shapes to conform and accommodate plumbing and utility service lines within the wall studs. It is installed simply by lifting and placing in the wall cavity.
Closed Cell Foam
With the highest insulation quality per square inch, closed cell foam insulation is a great wall insulation product. It is a chemically developed insulation sprayed into the cavity of the wall and “swells” or expands during application. Installation practices require prudent application as the product sets up quickly and in final position, so there is no adjustment once the insulation cures.