The stardard method for a well insulated flat roof is to put the thermal insulation on a concrete, steel or even wooden deck. In the case of cellular glass, the most popular method is still to push the boards into liquid hot bitumen. The hot bitumen rises in the joints and a certain overflow has to be present for a vapor tight roof. As a consequence, the weather conditions are rather stringent to construct a quality roof.

However, recently in Norway another method is used due to the availability of large monolithic cellular glass boards 2.8m x 1.5m x 0.18m from GLAPOR. The boards are assembled to large panels up to 8m x 2.5m x 0.25m thickness. Afterwards, the panels are coated with a reinforcing product. This work is done inside independent of the weather conditions.

Later on, the large assembled GLAPOR cellular glass panels are put on the roof with a crane and a final coating is performed on the top surface as waterproofing. These panels are self supporting which means that only beams are needed to support the roof. In principle, steel, concrete or wood deck are not necessary anymore in the roof structure, reducing significantly the cost.

The construction of the 25cm thick insulating roof panel is shown in the pictures. In our opinion, the future of cellular glass is to be used for large self supporting panels instead of only insulating structures. For the last option, plenty of low stiffness alternatives like XPS, EPS, MW, … are available. This future for cellular glass was born when Walter Frank at GLAPOR has built the first continuous foaming production line for larger sizes.