The uppermost layer of the forest is called the canopy. It consists of the tallest trees that form a continuous leafy roof over the layers below. The canopy provides shade, shelter, and food for many animals living in the forest.
the roof is double layered with provition for ventilation of the space between the 2 layers
Just 2 layers I recommend, because if you add an additional layer the roof will get damage and collapsed.
Torch-on roofing, also known as torch-down roofing, is a flat roof covering solution that consists of three layers of modified bitumen (felt) melt-welded to the roof surface and each other with a blowtorch to create an impenetrable, waterproof seal.
Around 35,000 dollars
Removing deep snow in layers and removing snow on both sides of a low-pitched roof as you go.
it is called a roof
The roof
Usually not more than two.
The thin piece of wood used to cover a roof is called ply board or deck board. Plyboard is a sheet material manufactured from thin layers or plies of wood veneer that are glued together.
The roof of the cavity is called the "dorsal surface."
It is what you called the planning for the roof.