Difference Between Regular Insulation & Attic Insulation

Wall and Floor Insulation

• Wall and floor fiberglass insulation sometimes comes with a hardy paper or foil adhered to one side of the insulation with asphalt. This serves as an additional moisture barrier and is only used on the envelope of the home--those areas that face the outdoors, such as external walls and underneath floors. When insulating with faced insulation, keep the facing toward the room as this prevents condensation on the interior of exterior walls. Use unfaced insulation for interior walls. It also provides sound-deadening qualities in addition to its insulating qualities.

Attic Insulation

• Insulation is rated for its resistance to heat flow and you'll find R-13, R-19 and R-21 in most walls. However, the ceiling requires, at minimum, double the insulation value found in walls. The minimum attic insulation, R-30 often doubles to R-60 in regions that require a higher resistance factor to heat flow. Different areas of the country use different R-value insulation. For instance, in the southwest part of the United States, an R-value of R-13 or R-19 is used for the walls and maybe R-30 or R-38 for the attic, while in northern climes, R-60 would typically be the R-value of the insulation in the attic.

Blown-In Insulation

• For attic spaces that are difficult to access, use blown-in insulation, which allows an easy fill up of the attic space with insulation. Looking much like white cotton candy or cotton balls, blown-in insulation adds high resistance values in the attic because it can fill in cavities and crevices quite easily. The added layering adds insulation value to the home's ceiling.

Insulation Types

• Consumers can choose between different insulation types. The most common type of insulation is fiberglass insulation; there's also insulation made from recycled newspapers, cotton insulation, insulation spun from mineral ore fibers, and combinations or variations thereof. Some people choose to use spray-foam insulation, but the installation process is highly toxic and takes days to dry thoroughly.

History

• Fiberglass insulation is made from natural materials, sand, silica, recycled glass, boron and other materials heated to extreme temperatures. It is then spun and bound together with an acrylic polymer, depending upon the manufacturer. The process of manufacturing insulation is patented; the company that holds the patents that the three largest fiberglass companies use--Owens Corning, CertainTeed and Johns Manville--is Saint Gobain, a 346-year old company as of 2011. Saint Gobain is based in France and is responsible for the construction of the mirrors in the Hall of Versailles.