Batt insulation: More Than a Few Cautionary Notes!

Batt insulation: More Than a Few Cautionary Notes!

Get up to $300.00 off spray foam and cellulose. Execution of work on July 15, 2024 or before, this discount is exclusive to owners of residential buildings (5% discount up to $300.00 maximum).

This type of insulation, which has been popular for years – and even decades – comes in two different forms, depending on its application: batt or blown-in.


To obtain effective insulation with fiberglass batts, you will need to add the following:

  • An air barrier
  • A vapour barrier
  • An acoustic sealant

Make sure that the insulation is fully sealed before you cover the wall with gypsum or any other material. After that, it will be too late!

Isolation Majeau recommends

When installing fiberglass batts, you must ensure that:

  • The cavity is evenly filled
  • You do not compress the material by more than 5 %
  • You place acoustic sealant on ribbon strips, side rails, sill plates, etc.
  • You install a continuous polyethylene vapour barrier (6 mm) that straddles the studs
  • You seal any holes in wires, pipes, etc., with a vapour barrier tape

If possible, ask a professional to verify the installation once it is is completed.

Stone wool: More Than An Insulator – A Firewall!

Stone wool is the ideal product for soundproofing or protecting a wall against fire. It has an R-value of 3.7 per inch, and it offers distinct features because it is:

  • Stable
  • Environmentally friendly
  • Sound absorbing
  • Flameproof
  • Water-resistant
  • Mould-resistant

Stone wool can be installed in batts or as blown-in. Stone wool batts are used to insulate walls. Thanks to its density and woven fibres, it is an excellent air and sound barrier.

A roof that is exposed to several heat sources could be insulated with blown Stone wool (for its fireproofing qualities). It is used in batts to insulate chimneys, among other things. Its unique properties make this product a premier protection against fire hazards.

Fiberglass Batt insulation: More Than Wool, More Than Fiberglass!

Looking for a cost-effective insulation for walls? Fiberglass wool is a good choice, with an R-value of 3.0 per inch. This product is now well known, having benefited from widespread advertising by world-class manufacturers such as Owens Corning.

Isolation Majeau recommends

  • Never apply fiberglass batts onto concrete foundations
  • Avoid applying it onto steel and end joists
  • Make sure that the air and vapour barriers are seamlessly installed, without even the slightest opening, and that you install an acoustic sealant