Most Glapor cellular glass is installed with hot bitumen 85/25, which is more or less the standard method. The bitumen is heated to above 180°C and poured on the substrate if possible.The cellular glass blocks are put into the liquid bitumen and pushed against the previous installed blocks. The liquid bitumen creeps upwards in the joints and flows slightly over the surface. This procedure guarantees a vapour tight roof free of internal condensation. Cellular glass, which cracks during this procedure, is not well produced. In case of a steel roof, the blocks are dimpled in hot bitumen bath with the bottom and two side surfaces and installed on the roof. Bitumen is indeed a nice and practical adhesive but it has some important disadvantages:
- Bitumen burns and is EUROCLASS F. It can be improved with fire retarders but these improved bitumens are rather hard to find.
- Bitumen has IARC classification 1 and has beyond any doubt cancerogenic risks, especially during installation when hot. This risk is reduced when working with cold bituminous products, like Pecimor-DK.
In case a roofing membrane is used, we need to use a flexible organic adhesive. Millennium one step green foamable adhesive is a good choice. It adheres on concrete, steel, wood and on glass. In case of uncoated GLAPOR cellular glass boards, we have a perfect large surface for adhesion.
Millenium one step green foamable adhesive has the following advantages:
- It can be applied in all climates but not on a wet surface. In warm and moist climates, it reacts fast.
- Mixing is not needed, it is a one step adhesive
- Due to the small foaming, it absorbs small irregularities in the surface.
- It replaces fasteners through the thermal insulation
- Equipment is available to reduce labor cost to a minimum.
GLAPOR advises to use this adhesive as an alternative to hot bitumen for reason of fire safety and health.