Hi everyone. I have a small flat roof that does not leak, but is getting old and blistering. It is on a 1925 house in New York City. The current roof is black tar on plywood, about 2 layers deep. The roof of the house is spray foam insulated on the underside, and it is a warm attic. There are various skylights in the roof that have slopped on tar as flashing. The house has a pitched, slate roof in the center, dividing the two flat roofs.
The contractor wants to cut open the blisters, and nail them down. He wants to then nail a thin layer of insulation on the existing roof, and then put "90 grade" (not sure what that is) paper with glue on top of the insulation. He will use metal flashing on the pitched roof and tuck it under the slate tiles. He will then coat it with aluminum paint. The job is $2,500. Pretty cheap. He says that as long as we re-coat it every 8 years, it will last "forever."
We hope to put some rubber mat on the roof and walk on it.
Is his plan a good one?
We have the budget for higher-end materials, would PVC or another material be superior?