Concrete bottom S40
Upon request, a boiler can include a concrete bottom with a sealing tape.
The room where the boiler is installed, must have the concrete floor (at least at the place where you stand in the boiler). The boiler is placed directly on the concrete floor and leaks between the floor and the boiler must be sealed with silicone which is resistant to heat, or with cement-lime mortar with sand or other materials). The boiler can be installed on a concrete floor for installation with a sealing rope.