Dry Hollow Floors

Dry hollow floors are classified to DIN EN 13213 in 1,000 N increments; typical constructions achieve 2 to 6 kN point load at a safety factor of 2.0, with reinforced builds exceeding this. They’re suitable for office, administrative and retail areas with normal furnishing. For control rooms and high-load data centres, a conventional raised floor is the better choice. We assess suitability on a case-by-case basis.

The dry hollow floor panels are made of non-combustible mineral materials (calcium sulphate or cement-bonded composite) and achieve building material class A1 or A2-s1,d0 to DIN EN 13501-1. Combined with the subsequent floor covering, the complete system typically falls into class B-s1,d0. F30 or F90 builds are available with tested system configurations.

The load-bearing panels are usually calcium sulphate screed elements, or alternatively cement-bonded fibre panels — both non-combustible and dimensionally stable. They’re laid dry on height-adjustable pedestals or support feet and bonded without any pour-in mortar. As a result, the floor is load-bearing and ready to receive a covering immediately after installation — unlike a poured hollow floor, which needs a drying period.

After installation, the joints are filled and the surface is sanded to create a level surface ready to receive a covering. For textile coverings, a primer is sufficient; for LVT, PVC or tiles, a 1–3 mm levelling compound follows. Unlike poured systems, the floor is ready for covering immediately after filling. We coordinate this interface with the flooring trade.

Yes, with the right preparation. A decoupling membrane, and where necessary a waterproofing membrane, is applied over the dry screed elements, after which porcelain stoneware, natural stone or ceramic tiles are laid using the thin-bed method. It’s important to choose a flexible tile adhesive that can accommodate movement at the hollow floor panel joints. We select format and panel thickness in coordination with the tiling contractor.

The dry hollow floor can be walked on immediately after the load-bearing panels are laid — this is its key advantage over the poured system. Heavy materials and furniture should only be brought in once the adhesive points and filler have cured (typically 24 hours). The floor is ready for textile coverings once filled, and for tiles once the decoupling membrane has set.

Yes, both. The void can be filled with mineral wool, insulation packages or acoustic absorbers — important for external areas, ground floors or acoustically sensitive rooms. Access hatches are provided via designated covers or removable panel sections. We agree the layout with the building services (M&E) design so that cable and ventilation penetrations don't need to be cut in laboriously later.

Standardised cut-outs for sockets, data outlets and ventilation grilles are generally included in the quote, provided the number and location are known before installation begins. Later or particularly complex cut-outs (large service hatches, bespoke geometries) are billed as an additional item. We recommend finalising all outlets during the design phase — this keeps costs down and avoids delays on site.