The existing flat roof, with the installed thermal insulation of smaller thicknesses, can be upgraded to a better energy performance roof, with an additional layer of thermal insulation.

FIBRANxps 300-L boards of adequate thickness are placed over the existing waterproofing layer, then two-level water drainage is carried out, using the same method as with inverted roofs, and then finishing layers are executed, according to our plans. Some hints can be found on “inverted roofs” page.

Composition of PLUS roofs

The existing composition:

• vapour barrier laid over the sloping board,
• thermal insulation,
• waterproofing layer

PLUS upgrade

• thermal insulation FIBRANxps 300-L of adequate thickness,
• upgrade depends on the finishing layers and the intended use of the inverted roof’s surface.

 Warning:

The immediate upgrade may be carried out only if the waterproofing membrane is intact and if the roof’s inclination is adequate. If not, the roof’s remedial work neds to be carried out first.