- Slope screed (>1 / max. 5%)
- Priming layer (oxidised bitumen, solvents and resins based primer, applied by brush or spraying in quantity of ~250 g/sqm)
- Vapour barrier with VELOBIT 3 mm membrane (VELOBIT 4 mm orNOVALL-I 3 mm for special situations), fully bonded on the verticals up to 10 cm above the level of the thermal insulation, and loose laid on the horizontal area
- Thermal insulation layer (when possible, spot welded by torching directly on the vapour barrier, or bonded with oxidised bitumen). In all cases, in order to guarantee the stability of the system, it is necessary to fix the thermal insulation elements with mechanical fasteners at least on the perimeter and in correspondence of protruding bodies. In case the thermal insulation is not flammable and presents high characteristics, the fasteners will be placed on the panel itself; otherwise, they must be placed on the first membrane.
- Double layer waterproofing system, made of:
a) first membrane: NOVATER 4 mm, offset in respect to the joints of the insulation panels, applied by torching, semi bonded on the horizontal area and fully bonded on the perimeter; laying of the second layer membrane will be preceded by the application of a strip of membrane (NOVATER 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: NOVAMINERAL 4,5 kg applied by torching in total adherence to the first one and on the verticals.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 (15 cm in case of mineralised membranes). Vertical walls and other protruding structures must be waterproofed with the same type of membrane, possibly mineralised.
In case of special situations characterised by significant thermal cycles, elastomeric membranes must be used:
– NOVAGUM-P 4 mm as base sheet
– NOVAGUM-P MINERAL 4,5 kg as cap sheet
It is always advisable that the cap sheet will be self protected with mineral sates chips or paints, for protection from atmospheric agents and to satisfy aesthetical requirements.