Knauf: Polyfoam Floorfoam: Concrete Planks (twin layer)

This system consists of a floating screed on a double resilient layer.

The screed to have a nominal density of 80 kg/m2 and be either:

• 65mm (min) sand:cement screed, or
• 40mm proprietary screed The upper resilient layer to be Polyfoam Floorfoam 5.

The lower resilient layer to be 25mm Rocksilk Acoustic Floor Slab Plus or 25mm Polyfoam Floorboard Standard.

The edge detail consists of two separate edge isolation layers:-

• First Edge Strip - Running up the wall from the sub floor to the level of the drylining, isolating the whole system.
• Screed Isolation Strip - Isolating the screed from the whole system.

The concrete floor to be 150mm (min) precast concrete floor plank of at least 300 kg/m3, with all joints fully grouted.

Ceiling treatment CTO is shown above, for precast planks 200mm deep, the Robust Detail offers a choice of 2 other ceiling treatments.

Typical acoustic performance

Tested to BS EN ISO 140-3: 1998 and BS EN ISO 140-6: 1998 and analysed according to BS EN ISO-717-1: 1997 and BS EN ISO-717-2: 1997.

Fix the first Easy Edge Strip, using the self adhesive strip, at the base of the wall for the entire perimeter of the floor.

The first Easy Edge Strip does not lap onto the floor, and sits flat on the wall running from the subfloor wall junction to the bottom of the drylining and skirting.

Lay the 25mm Resilient Layer in accordance with manufacturers instruction.

Fix the second Easy Edge Strip layer to act as a Screed Isolation Strip to the first Edge Strip using the self adhesive strip on the rear. The strip should be positioned as shown in the diagram above with a 40mm lap onto the 25mm Resilient Layer.

Lay the 5mm Resilient Layer. At the perimeter it should be lapped across the full width of the horizontal portion of the Screed Isolation Strip and the joint taped.

Lay the screed according to manufacturers instructions, DO NOT TRIM THE EDGE STRIPS at this stage. When Fixing the Lining (either Plasterboard or Wet Plaster) fold the Screed Isolation Strip flat to the Screed. DO NOT TRIM THE SCREED ISOLATION STRIP AT THIS STAGE.

When fixing the Skirting Boards fold the Screed Isolation Strip flat to the screed so that the strip isolates the Skirting board from the screed. Trim the screed isolation strip flush with the face of the skirting board.

Trim the screed isolation strip flush with the face of the skirting board.

Benefits

• Former Robust Detail solution
• Ideal for use with underfloor heating
• Allows thermal and acoustic insulation for intermediate floors

Suitable for use with Underfloor heating systems:

Where underfloor heating is specified, the Rocksilk Acoustic Floor Slab Plus is replaced by the pocketed polystyrene Osma underfloor heating system. In this detail, the Polyfoam Floorfoam 5 is laid below the pocketed polystyrene boards. Please note the same attention to isolation as above is crucial.