Inverted roof installation
The Inverted Roof Concept, which is also known as protected membrane or upside down roofing ensures insulating both the water-proofing membrane and the reinforced concrete slab from extreme thermal stress.
This is acvhieved by placing ISOBOARD® extruded polystyrene thermal insulation board above, instead of below, the waterproofing membrane.
Typical uses for ISOBOARD® in this applicaiton:
Installed either as new or retro-fit.
Insulation above water-proofing membranes on flat topped buildings or balconies, in retail or office developments, flats, hospitals, airports, hotels and in residential housing.
Ballast the insulation board to prevent wind uplift and flotation and to protect the ISOBOARD® from UV radiation:
- using gravel where no traffic is envisaged;
- using paving slabs where pedestrian traffic is envisaged;
- using light weight concrete screed to falls where drainage is important;
- and below a flexible road pavement or reinforced concrete slab for parking decks.
The following depths of gravel are appropriate but consideration needs to be given to the likelihood of extreme conditions and the structure of the building (eg: the existence and height of parapets):
|
Board Thickness
(mm) |
Gravel Depth
(mm) |
|
50mm |
50mm |
|
60mm |
60mm |
|
70mm |
60mm |
|
75mm |
65mm |
|
80mm |
70mm |
|
100mm |
80mm |
|
120mm |
90mm |
Gravel should be about 15-30mm normal size natural aggregate, reasonably clean and free from large amounts of fines.
