Can PIR insulation boards be used directly below flooring tiles?
No, PIR insulation boards should not be used directly below flooring tiles, a suitable substrate such as screed should be used to distribute the load and prevent movement and cracking of the tiles.
Is a vapour control layer (VCL) required in a floor insulation application?
In addition to the damp proof membrane (normally a 1200-gauge polythene sheet below the insulation), a 500-gauge polythene VCL should be laid over the insulation. Where a concrete slab or a screed is to be poured on top, the VCL will also protect the foil face of the board from alkalis within the concrete, and stop poured concrete opening board joints and causing a thermal break.
What insulation products can be used with underfloor heating?
Recticel Insulation's Eurothane® GP boards are compatible with both wet and electrical underfloor heating systems. Clipping a wet system through the VCL described above will not compromise the performance of the VCL or the insulation.
What membranes are required in flooring application when using Recticel PIR insulation boards?
For installation on a concrete slab it is recommended that a damp proof membrane is installed below the insulation and then an additional vapour control / separating layer above the insulation before the screed / floating floor finish.
For suspended floor applications such as timber joists there should be the vapour control / separating layer included again before the finish of timber or screed.
When installing Recticel PIR insulation boards on a suspended timber floor can it be put directly onto joists?
No, a suitable timber substrate should be included over the joists (minimum 18mm) before installing the insulation.