The advantages of extruded polystyrene foam can be utilised mainly in ground-bearing floor structures. Beside a traditional insulated floor build-up - where the ROOFMATE™ SL-A insulation is placed on the waterproofing membrane laid on a concrete slab - the negligible water absorption and the zero capillarity of extruded polystyrene foam enable the use of the inverted floor insulation method - the ROOFMATE SL-A boards are placed directly on 10-15 cm compacted and levelled hardcore. Over the insulation a PE-foil is placed to prevent the concrete, of the load distribution slab/screed, running through the joints. The PE-foil also plays a role in protecting against moisture transport. However, in the case of damp soil, a waterproofing membrane should be installed on the top of the concrete slab/screed.
ROOFMATE SL-A boards also offer efficient and long-term solutions for the insulation of intermediate residential floors:
floors above unheated spaces,
The extruded polystyrene foam boards act only as thermal insulation. For impact sound protection a separate layer should be installed.