How to Cover a Flat Wood Roof

Sweep the roof to remove all visible debris and dust from the surface.

Cut a piece of roofing rubber to a size that is 10 inches wider and longer than the roof measurements. Lay the rubber sheet on top of the roof so the excess hangs evenly off each side of the roof.

Cut holes into the rubber covering so you can pull the cover over the top of vent holes, chimney or pipes protruding from the roof. The edge of the cutout should be flush with the edge of the obstruction on the roof.

Grab one edge of the rubber covering and fold it over the opposite half of the roof so the folded edge is in the center of the roof. Fold the rubber cover to the edge of a pipe or other protrusion on the roof, if applicable.

Spread rubber contact cement over the surface of the exposed half of the roof. Let the cement dry to the touch before laying the rubber roof covering in place.

Attach the rubber to the roof by gradually unrolling the overlapped half of the rubber sheet and pressing it into the cement. Work slowly and unroll the rubber instead of stretching it over the cement in one application to prevent air pockets or wrinkles in the covering.

Repeat the rubber covering application on the other half of the roof in the same manner.

Pull the excess rubber over the edge of the roof. Cut off the excess so there is about a 2- to 3-inch overhang. Clip the corners from the point on the rubber covering to the edge of the roof. Fold the corner so the rubber is flush against the roof.

Secure the overlapped rubber to the edge of the roof with contact cement. Attach the covering to the edge of the roof with a strip of metal flashing with finishing nails set about 4 inches apart.

Apply a strip of tri-polymer caulk around the edge of the roof where the rubber meets the roof edge and along the corner seams. Apply caulk around the edge of cutouts made on the roof to secure the edge to the vent, chimney or pipe and prevent moisture getting under the rubber covering.