Is It Okay to Shingle Over Rolled Roofs?

Types of Shingles

• Any type of shingle can be installed over the top of roll roofing, including asphalt shingles, wood shakes or slate. While each of these shingle types provides a different appearance to a roof, they are made in similar ways and, therefore, have similar installation methods. Of these three roof types, asphalt shingles are the least expensive, but they also provide the least protection to the roof. Slate shingles are the most fragile when handling and wood shingles provide adequate protection, but are prone to mildew and can be a fire hazard.

Cleaning Up the Roof

• Before attempting to shingle over rolled roofs, you should ensure that the surface of the roof is clean. Any loose debris on the roof, like leaves and limbs, can be picked off by hand, and the entire roof should be swept with a broom to remove loose debris and dust. After removing loose debris, spray the rolled roof with the hardest setting on a garden hose to remove any dirt, using a cleaning brush on any areas where dirt sticks to the surface. Let the roof dry completely after cleaning before installing roofing.

Laying Shingles

• To lay shingles over rolled roofs, always begin at an eave of the roof, just as you would for any standard roofing job. Shingles should be installed so that they overhang all of the roofs edges slightly and line up side by side. All types of shingles are laid in rows with the shingles in each row touching on their edges and each row overlapping the row of shingles below.

Finishing the Shingled Roof

• Since shingles are laid from the bottom of the roof up, the peak is always the last part of the shingling job, and the way that the peak is shingled depends upon the type of shingles. Flexible shingles like asphalt should be bent over the peak of the roof, while hard shingles, like wood, must be overlapped at the peak to create a barrier. Once the shingling job is done, you should apply waterproof sealant to any exposed nail heads in the shingle job to prevent leaks.