LooseLay Installation Guidelines

Subfloor Preparation 

Subfloor preparation must comply with ASTM F710, AS/NZS 1884, BS 8203, DTU 53.2, DIN 18365 (Teil C) or other applicable National Standards and Building Codes for the installation of Resilient Flooring and in strict accordance with the following installation guidelines. 

The subfloor must be dry, smooth, level, clean and dust-free and should be prepared as follows, dependant on your subfloor type. Note: Solvents and other abrasive chemicals used to clean or remove subfloor contaminants can damage the backing of Karndean LooseLay and affect the product’s performance. 

Old Adhesive residues 

All adhesive residues from previous installations must be completely removed. 

Damp Subfloors 

Karndean LooseLay must only be installed on dry floors. The floor must have a moisture reading of less than 95% RH (or according to the National Standard). If any sub floor shows moisture readings above 95% RH then an acceptable damp proof membrane/moisture suppression system must be applied. 

Note: that a compliant pH level is also a requirement for concrete slabs in some countries’ Standards. (If using the calcium chloride test procedure ASTM 1869-11 the reading must not be above 5lbs per 1000sq ft. per 24hrs). 

Concrete Floors 

Subfloors/Screeds: All cracks and joints must be filled using a cement based patching compound and the floor needs to be level in accordance with the applicable Standard.

All Gypsum based concrete floors must be sealed with a compatible sealing compound. 

Mosaic/Terrazzo/Ceramics/Quarry Tiles 

Level any grout lines with a suitable smoothing compound and make the floor sound. 

Timber Floors 

These should be solid with minimal flexibility. All loose boards must be firmly fastened, gaps filled and undulations removed.Where necessary, overlay floorboards with flooring grade  plywood or similar. 


Make sure these floors are solid; fix any loose tiles and remove any surface polish/sealer. 

We recommend the removal of these products if installed directly to earth, bitumen/ cutback or pitch. Then prepare floor to applicable Standard. 

Metal and Painted Floors

Fully remove any loose paint or other finishes. 

Other Floors 

Consult your supplier.

Underfloor Heating and Services

Karndean LooseLay is suitable over underfloor heating systems, as long as it is insulated from the heating system to ensure that the surface temperature does not rise above 27°C (80°F). 

Note: The system must be switched off 48 hours before, during, and for 48 hours after the installation; then the temperature should be gradually increased (typically 2°C/hour) to the desired warmth. Mesh/wire systems must be bedded into a base coat of reinforced fibre smoothing compound. Refer to manufactures guidelines for required depth. Karndean LooseLay installation methods are then followed as recommended in these guidelines.

Karndean LooseLay allows easy access to under floor services if installed over access panels, provided the resultant subfloor complies with the values stipulated in the relevant Building codes and Standards.

Please note that before installing Karndean LooseLay, you should refer to our full installation instructions.