batt and blanket insulation

Batt and blanket insulation is used in new construction and in retrofits, and differ in price and uses according to their different densities and thicknesses.

Batt and Blanket insulation materials

Insulation blankets (batts and rolls) are mainly made from fiberglass and rockwool. Mineral wool (rockwool and slag wool) batts are common in Canada, Europe and other countries, but much less common in USA, where fiberglass batts are largely dominant.

Blankets, rolls, batts and their uses

Insulation blankets may come in continuous rolls that are cut to fit in non-standard places.

Insulation batts are offered in standard widths, particularly suited for new construction, where they are installed between the building cavities. They are mostly used to insulate standard spaces in walls, attics and ceiling and floor joists (in retrofits).

Rolls are available in 3-6 feet wide units. They are largely used in applications like duct, tank and pipe insulation and soundproofing.

Faced and unfaced batts

Faced batts include an air/vapor barrier (to fight indoors moisture) and are very common. If using a faced batt, prefer a non-vinyl one (kraft and foil-kraft faced batts...) for environmental reasons. Vinyl is a rather poisonous material in their manufacturing.

If adding new insulation over existing one, you should use unfaced batts.

Flame and water resistant batts

Water resistant batts are particularly suited for basement walls or whenever insulation is left exposed. Mineral wool and fiberglass insulation batts are very water-resistant in themselves, which is an important element to take into account in many situations.

Besides insulation blankets and batts with water-resistant facings, there are also those with fire-resistant facings.

Low, medium and high-density batts

Older and more standard insulation blankets and batts have relatively low-densities and, consequently, relatively low insulation value (R-value): something around 3-3,8 per inch of thickness. They are also the most inexpensive.

Medium and high-density blankets are newer types of insulation, with 2 to 3 times the density of older low-density batts (R-values around R-3.8 and R-4.3 per inch). That means that older 3 ½ inch batts have a R-value of 11, while medium and high-density batts have a R-13 to R-15 (or around R-21 for 5 ½ inch batts).

The higher insulation value of newer high density batts and blankets is an important feature in applications where space (for insulation) is scarce.

Insulation Batt/Blanket costs

The cost of blanket and batt insulation vary with manufacturers and mainly with its thickness (inches) and density.

Expect prices around...

- 12-15 cents/sq. foot for 3 ½ inch batts (R-value 11);
- 35-40 cents/sq-foot for 5 1/4 inch batts (high density).

Higher-density batts with 8 to 12 inches per square foot (R-values around 30 – 40) will cost you a bit more: between 40 and 60 cents per sq. foot.

Installation cares

The effectiveness of batt-blanket insulation depends largely on the quality of the installation. Batts should be cut exactly, and fill the cavities completely.

They shouldn’t be too long or too short. Compressed batts will have their effectiveness reduced up to 30%. Splits and indentations of the insulation material will also reduce their insulation value.