Insulating Your House from CMHC Series 4-10

Effective Insulation Systems

Effective insulation systems slow the movement of heat and deal with the movement of moisture at a reasonable cost. To do this, they have the following:

• An air barrier, which prevents the movement of interior or exterior air through the system.
• Carefully filled cavities, which leave no gaps in or around the insulation and which do not compress the insulation.
• A minimum of thermal bridges. These are parts of the wall that, with a lower R value, extend from the warm side to the cold side of the insulation, giving heat an easy escape. The structural members in the wall will often be thermal bridges.
• A vapour retarder, such as polyethylene sheeting, which prevents moisture from moving from warm interior spaces into a colder building envelope where it could condense.
• Drying potential, which is the ability of the insulated assembly to release