Which material can be used to increase a roof's insulation value?

The choice regarding a felt interlay signifies an understanding of roofing materials and their properties, particularly concerning insulation. A felt interlay, often made from materials like fiberglass or organic felt, is designed to provide an additional layer within roofing systems. Its installation under shingles or tiles contributes to better thermal performance due to its ability to trap air, thereby reducing heat transfer.

By incorporating a felt interlay, homeowners can enhance the overall insulation value of the roof, which leads to improved energy efficiency. This indicates that the structure is better at maintaining indoor temperatures, which is particularly beneficial in extreme weather conditions. This aspect helps in reducing heating and cooling costs, making it a valuable component of roofing systems focused on energy conservation.

Other materials listed, such as wood shingles, clay tiles, and concrete, are primarily chosen for their durability and aesthetic qualities rather than for insulation properties. While they may provide some level of thermal resistance, they do not specifically enhance the insulation value to the same extent as a felt interlay.