It is based on steel, four millimeters thick.

What are the caissons? It can be made of a variety of materials! Consider some of them in more detail!

Metal caisson. It is based on steel, four millimeters thick. To protect steel, most often on the outside it is covered with bitumen, and inside the primer. When buying a kesson of this type, special attention should be paid to the quality of welding — from how high -quality the sheets of steel will be cooked together and sealing depends.