How Does it Work?

The TETRiS flooring system comprises three different types of extruded polystyrene (XPS) insulation blocks. When connected together, they form a flat fixed level above the concrete beams with zero cold bridges, on which a structural concrete finish is laid.


1. T-blocks: large insulation blocks (0.75m2 or 1.5m2 ) profiled to suit specific pre-stressed concrete floor beams used. The blocks 75mm upper section sits on the beams, and the lower section (15mm – 85mm) hangs between.

2. Gap strips: 75mm thick insulation blocks, used to make up areas that T-blocks do not cover.

3. Vertical edge strips: Supplied to suit the thickness of concrete finish (65mm or 75mm), fixed around the floor’s external perimeter to eliminate cold bridging.
TFIX: fixing pins used to secure the strips in position.

Structural Floor Finish

To give the floor its structural integrity, the TETRiS blocks must be covered with an in-situ concrete topping.

C25 concrete with steel reinforcement – 65mm (min) concrete complying with BS 8500 Part 1, 2: 2002 and BS 206-1 with a maximum aggregate size of 10mm, poured over a minimum D49 steel reinforcement mesh to EN 10080: 1996, set at mid height on spacers.

C30 concrete with fibre reinforcement – 75mm (min) RC30 concrete complying with BS 8500 Part 1: 2002, with a maximum aggregate size of 10mm, combined with polymeric monofilament fibres at a rate of 900 g/m3.

C35 concrete – 75mm (min) RC35 concrete with a CEM1 Slump Class 3 to BS 8500 Part 1& 2: 2002, with a maximum aggregate size of 10mm.

Lafarge Agilia Horizontal – 75mm (min) proprietary self-compacting concrete, containing admixtures to BS EN 934, mortar and grout.