Interflashing: Enhancing Roof Durability and Weather Resistance

Interflashing is a term used in roofing to describe the process of installing two or more layers of shingles overlapping each other. This technique is used to provide additional protection against wind and weather, as well as to improve the overall durability of the roof.

When installing interflashing, the upper layer of shingles is placed so that its edges overlap the lower layer by about 2 inches. The lower layer is then covered with a special underlayment material that helps to seal the gap between the two layers and prevent water from entering the roof.

Interflashing can be used in a variety of situations, including:

1. High-wind areas: Interflashing can help to strengthen the roof and resist wind uplift, which can be particularly important in areas prone to high winds.
2. Steeply pitched roofs: On steeply pitched roofs, interflashing can help to prevent shingles from sliding or blowing off due to wind or weather.
3. Roofs with multiple hips and valleys: Interflashing can be used to provide additional protection in areas where there are many changes in direction, such as hips and valleys.
4. Roofs with skylights or other penetrations: Interflashing can be used to seal around skylights or other penetrations in the roof, helping to prevent water from entering the roof.

Overall, interflashing is a valuable technique for improving the durability and weather-resistance of a roof, and it can be particularly useful in certain situations where additional protection is needed.