Attic insulation

April 4, 2023

Insulation is an integral part of a healthy roofing system. It has an important impact on the formation of ice on the roof as well as on the energy consumption of the building. Thermal value is calculated in R-value and the current building code requires an R-value of at least 41. Indeed, below this rating, the insulation is considered inadequate. There are three types of insulation that are widely available on the market. The first type is batt insulation, which can be made of fiberglass or rock residue, and its thermal value varies between 2.85 and 4R per inch. The disadvantage with this type of insulation is the space between the batting since it leaves a small uninsulated area that spreads throughout the attic. The second type is blown insulation which can be made of fiberglass or cellulose and whose thermal value varies between 2.85 and 3.7R per inch. This type of insulation is much more efficient since the insulation is uniformly sealed without heat loss. The third type of insulation is sprayed polyurethane which is made of 80% recycled plastic bottles. Thanks to its assembly of two substances, it creates a rigid, manufactured and efficient insulation. Its R-value is 6 and from 1.5″ thickness, it becomes a vapor barrier.

Air sealing in the attic of older homes is often neglected. Indeed, the materials formerly used during construction were wool batting and built-in craft paper acting as a vapour barrier. However, the holes made to let through the electrical wires, the plumbing, the unsealed joints as well as the renovations made over the years, result in an insulation that has become completely ineffective. An update is therefore essential since research shows that a crack equivalent to 2 cm lets through an average of 30 liters of water per day. This causes condensation on the underside of the roofing support and also creates mold and deterioration of the attic insulation as it becomes saturated with moisture. In order to respect all the standards of today’s industry and to guarantee a quality and durable work, we favor a hybrid thermal insulation. It is composed of polyurethane and blown cellulose so that the insulation is waterproof and meets the standards of the current building code.

Indeed, there are several benefits to a good insulation of your roof such as you will enjoy a more comfortable temperature inside your home, you will reduce your consumption of air conditioning and heating throughout the year and finally, it will reduce your electricity bills.