Air Sealing and Insulation

Why your home is cold and drafty? Because of the stack effect that can be minimized by air sealing.

The stack effect is a cyclical flow of air driven by differences between indoor and outdoor air densities and temperatures. During the heating season hot air escapes throught cracks and openings on the top floor and sucks in cold air through openings and cracks on ground floor and basement. The reverse occurs during the cooling season: cold air escapes through openings and cracks on the ground floor and sucks in the hot air from outside through cracks and openings on the top floor and attic.

The best way to remedy the stack effect is by air sealing the house. Air sealing means tightening the house to minimize gaps between indoor and outdoor spaces. Tightening the house reduces the air leakage that the stack effect causes, while saving energy and improving comfort.


Insulation is absolutely necessary for your home because it resists heat flow – the higher R-value per inch it has the better. Insulation that resists air flow is preferable to air-permeable insulation. Choosing the insulation we make sure that particular material it is appropriate for its intended location and it will perform well, and of course is not beyond your budget. We at JL Construction install the following types of insulation:

Type of insulation

R-value per inch

Fiberglass batts

 3.2 – 3.8

Blown-in cellulose

 3.2 – 3.8

Dens-pack cellulose


Rigid foam boards

 3.6 – 6.5

Spray foam

 3.5 – 6.5

Injection foam

 3.5 – 6.5

Pour-in foam

 3.5 – 6.5