Can you put roll roofing over shingles?

It is not advisable to install roll roofing over existing asphalt shingles. While it is possible to temporarily cover damaged shingles with a layer of roll roofing as a temporary fix, this method is not a long-term solution and can cause several issues:

1. Improper Ventilation: Installing roll roofing over shingles can trap moisture and impede proper ventilation, which is crucial for preventing moisture damage to the roof deck and underlayment.

2. Weight and Structural Issues: Roll roofing adds additional weight to the roof structure, which can be problematic if the underlying roof and support structure are not designed to bear the extra load.

3. Improper Bonding: Roll roofing may not adhere properly to the existing shingle surface, leading to separation and curling of the roofing material.

4. Uneven Appearance: Applying roll roofing over shingles will result in an uneven surface, compromising the aesthetic appeal of your roof.

5. Building Codes: Some local building codes may not permit the installation of roll roofing over shingles.

It's important to note that the best practice for repairing or replacing a damaged roof is to remove the affected shingles and install new ones. This will ensure a proper, long-lasting repair and maintain the integrity and functionality of the roofing system.