The construction crews were removing a "gravel roof" and replacing it with a "TPO" (Thermoplastic Polyolefin) roof. The gravel roof consists of metal decking, foam (about 2"), tar, and gravel. This particular roof had two layers from a previous remodel. The foreman on site said city code only allows for two layers so they had to remove both layers before installing the new roof. The building across the parking lot only has one layer so they will put the new roof directly on top.
The TPO roof consists of metal decking, insulating foam (3.3" in this case), and the TPO membrane. The foam may be thicker in other applications. The foreman said a 1/2" of foam adds 6 to the R-value.
Old roof, two layers.
New foam layer, the TPO membrane is being pulled back.
Stacks of foam insulation.
So what's your plan to cut? Will you handle the gravel roof differently from the TPO? The rotary saw probably will not go deep enough on one pass. If you use a rotary saw you will likely have to make one cut remove the material and them make a second cut inside the first. The chain saw will work on many of these materials but you have to be careful about hitting metal beams as they can throw or break the chain.
10' drop off behind parapet.
From the inside.
Void space in the parapet.
Interior of building.
Forcible entry discussion. How would you handle this door? We discussed starting traditional but it probably would not work. With a good size-up and prior knowledge you might realize this is a panic/drop bar that is most always engaged. It is not removed everyday like a traditional drop bar.
We discussed cutting the bolts or completely cutting a rectangle around the pair of bolts. Last resort might be a doggie door (horizontal cut, edge to edge under the panic hardware.
Take a look around out there after your next call and see what you find.
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