Roofing is the most exposed part of a building, protecting it against rain and snow, cold and heat. It is also resistant to concentrated and distributed loads. It is also a significant architectural element that gives a building its typical shape.  The most widespread roofing in Italy is sloped roof on slab made of tiles elements covered by cement. In case of thermal insulation on bituminous membrane, we recommend using an insulating material with low or no water absorption like X-FOAM^® HBD. Extruded polystyrene is highly recommended in this type of application thanks also to its high compressive strength and low water vapor diffusion coefficients. The waterproofing membrane is usually laid on the load-bearing structure starting from a joggle in theeaves. The extruded polystyrene boards are laid dry. Special attention must be focused on micro-ventilation below tile. It is necessary to alleviate sharp differences in temperature, dry any water seepage and prevent the forming of condensate in the layer below the tiles. Micro-ventilation below the tiles is achieved by means of ledges in mortar of cement or a single of double frame of wood strips providing support for the tiles as well as the necessary ventilation.

Warnings:
Avoid using adhesives or membranes that release solvents not compatible with extruded polystyrene. In case of extreme weather or wind conditions, it is always recommended to duly fasten the tiles to the strips or slab.