- Sloping screed (2 · 3%)
- Adhesion promoting layer (primer with basis of oxidised bitumen and solvents, applied by brush or spraying, in such quantity to allow the perfect bonding of the layer, avoiding any delamination phenomena).
- Double layer waterproofing system, made of:
a) first layer: NOVATER 4 mm, applied by torching, completely bonded both on the horizontal surface and on the verticals; laying of the second layer membrane will be preceded by the application of a strip of membrane (NOVABOND PONTI 4 mm) having 30 cm width, welded for 10 cm both on the flat and on the vertical (therefore leaving free the corner);
b) second layer: NOVABOND PONTI 4 mm applied by torching in total adherence to the first one and on the verticals, up to a height of 20 cm above the level of the bituminous conglomerate.
For double layer systems, it is always advisable to lay the cap sheet in longitudinal direction respect to the base sheet, arranging the overlaps by having the ones of the upper layer in the middle of the first layer sheets. The sheets must be laid as well in such way that head overlap are staggered in longitudinal direction by at least 100 cm.
The joints must be made by torching, overlapping the membranes (laid as “tiles”, in the direction of the slope, to favour the down flow of the water), for at least 8 cm in the case of the side and 12 cm for the head. Vertical walls and other protruding structures must be waterproofed with the same type of membrane, possibly mineralised. Application in single layer (mandatory in the case of ramps with 5 · 10% slope), if foreseen for flat roofing, must be made with a NOVABOND PONTI 4 mm membrane, laid in total bonding both on the substrate and on the verticals according to the above indications.
- Flooring in bituminous conglomerate with 5 cm minimum thickness.
In case of special situations characterised by significant dynamic loads and/or strong thermal cycles, for the double layer system, as an alternative, a NOVAGUM-P 4 mm elastomeric membrane can be used in the first layer.
No thermal insulation must be foreseen below the bituminous conglomerate layer. In case the use of insulation is compulsory, it is necessary to use concrete flooring and insulation panels having characteristics which may guarantee the necessary safety level. It is always advisable to protect the waterproofing layer above the level of the floor (on the verticals) with a layer of cementitious mortar, reinforced with light metallic mesh.