Repairing a Flat Roof with GAF TopCoat

This homeowner had a sun room company build this sun room onto the back of his house. With time, however, it began to leak. The roof was flat sheets of metal (with a sort of “orange peel” texture, and paint baked on) joined with seams. Caldwell’s Roofing advised repairing a flat roof with GAF TopCoat product to fix the problem.

TopCoat is an elastomeric roof coating product. First, the suspect seams, screw heads, etc., are hit with a coat of the Flashing Grade and mesh is rolled and embedded into the coating. GAF’s TopCoat product has two products – the “Flashing Grade” is a 5-gallon container with a red top, and the “Membrane” is a 5-gallon container with a blue top. Both products themselves are white, and both are called “TopCoat.” The “Flashing Grade” is a sort of “primer” product, that helps the “Membrane” to better adhere.

Before applying either product, degreaser is used to “etch” the metal a bit to provide for a stronger adherence of the Flashing Grade TopCoat.

The picture above shows the roof after having finished the first step, which is applying Flashing Grade TopCoat and mesh to the suspect areas.

Next, after allowing the product to cure for a day, the Flashing Grade Top Coat is applied over the whole surface of the roof, as seen above.

After that has cured for a day, a layer of Membrane TopCoat is applied over the roof. Then, waiting yet another day for that to cure, a final second coat of Membrane TopCoat is applied. In the picture above, all steps have been completed. This roof repair ran $1,855, came with a 5-year proper-installation warranty, and should be a fairly long-term way to address this prematurely failing roof.