Which type of insulation is most commonly used in attics?

Loose-fill fiberglass or cellulose insulation is the most commonly used type of insulation in attics due to several key factors. This form of insulation is known for its versatility and ease of installation, making it ideal for attics which often have irregular spaces and hard-to-reach areas.

Loose-fill fiberglass is manufactured from recycled glass and sand, providing good thermal resistance (R-value) and fire resistance, while cellulose insulation typically consists of recycled paper products treated for fire resistance. Both materials can effectively reduce heat loss in the winter and limit heat gain in the summer, contributing to overall energy efficiency.

The application method allows for easy filling of gaps and spaces, which may not be as straightforward with other types of insulation like rigid board or foam insulation. This effectiveness and adaptability make loose-fill fiberglass or cellulose insulation a practical choice for homeowners seeking to improve energy efficiency in their attics.

In contrast, foam insulation and rigid board insulation are generally used in other areas of the building envelope due to their rigidity and specific applications. Reflective insulation is more suitable for climates where radiant heat gain is a concern, but it does not provide the all-around thermal protection achievable with loose-fill materials.