Most insulating materials are available in several common forms-loose-fill or spray-applied materials, blanket rolls, batts, boards and foil-faced paper, foam, film and cardboard. Each form is ideal for specific insulating jobs.
The type of insulation material you select for any job depends on how you intend to use it, how much you want to spend, and how easy it is to install.
The chart below provides a summary of the qualities and suggested uses for the basic types of insulation.
Study the chart carefully. Consider the advantages, disadvantages and instructions for using each type of material as outlined in the chart. This table should help you select the correct material for any insulation job.
Blanket and batt insulation is usually made from fiber glass or rock wool. It is sized to fit between studs, floor joists and ceiling joists. It comes both faced and unfaced. Faced means the batt or blanket has a cover such as paper or foil on one side. Unfaced means there is no cover. Some batts and blankets now come with a protective covering that reduces the ‘itchy feeling’ you get when you work with insulation.
Rigid foam insulation is widely used on basement walls and on exterior walls. If rigid foam is used inside, it must be covered with gypsum board or other building code-approved material for fire safety reasons. When it is applied on the outside, it must be covered with a weatherproof facing. When using a foil-covered rigid foam, the foil must be away from the heated side of the wall to avoid a condensation problem.
Types of Insulation
|Form||Method of Installation||Where Applicable||Advantages|
|Blankets: Batts or Rolls; Fiber glass Rock wool||Fitted between studs, joists, and beams||All unfinished walls, floors and ceilings||Do-it-yourself; Suited for standard stud and joist spacing, which is relatively free from obstructions|
|Loose-fill (blown-in) or Spray-applied; Rock wool; Fiberglass; Cellulose; Polyurethane foam||Blown into place or spray applied by special equipment||Enclosed existing wall cavities or open new wall cavities; Unfinished attic floors and hard-to-reach places||Commonly used insulation for retrofits (adding insulation to existing finished areas); Good for irregularly shaped areas and around obstructions|
|Rigid Insulation; Extruded polystyrene foam (XPS); Expanded polystyrene foam (EPS or beadboard); Polyurethane foam; Polyisocyanurate foam||Interior applications: Must be covered with 1/2’gypsum board or other building-code approved material for fire safety; Exterior applications: Must be covered with weather-proof facing||Basement walls; Exterior walls under finishing (Some foam boards include a foil facing which will act as a vapor retarder. Please read the discussion about where to place, or not to place, a vapor retarder); Unvented low slope roofs||High insulation value for relatively little thickness; Can block thermal short circuits when installed continuously over frames or joists|
|Reflective Systems; Foil-faced paper; Foil-faced polyethylene bubbles; Foil-faced plastic film; Foil-faced cardboard||Foils, films or papers: Fitted between wood-frame studs, joists and beams||Unfinished ceilings, walls, and floors||Do-it-yourself; All suitable for framing at standard spacing. Bubble-form suitable if framing is irregular or if obstructions are presentt; effectiveness depends on spacing and heat flow direction|