Where is air-permeable insulation installed in the Air-permeable Insulation Method?

In the Air-permeable Insulation Method, air-permeable insulation is ideally installed below the roof sheathing. This placement allows the insulation to effectively trap air within its structure, which contributes to its thermal performance. Additionally, positioning the insulation in this manner helps to maintain the thermal envelope of the building while managing potential moisture issues through ventilation strategies.

When installed below the roof sheathing, air-permeable insulation can assist in ensuring that warm, moist air generated inside the building does not condense on cooler surfaces, thereby reducing the risk of moisture-related problems in the roof assembly. This method supports effective airflows, which is critical for controlling humidity levels and improving indoor air quality.

Other placement options, such as above the roof sheathing, adjacent to the walls, or between ceiling joists, may not provide the same benefits in terms of moisture management and energy efficiency, potentially leading to air leaks and compromised insulation performance.