The preparation required is dependent on the depth of screed and/or levelling compound required in order to make up the necessary levels and/or falls (which typically range from 1/35 to 1/80):
- Where just a thin smoothing layer of 2-20mm is required, firstly use suitable mechanised equipment to remove any contamination and reveal the aggregate underneath. It should then be levelled with a suitable external levelling compound such as ARDEX K 301.
- When up to 50mm is required, first prepare as above and then screed with ARDEX A 38 or ARDEX A 29 bonded with ARDEX A 18.
- When over 50mm is required, mechanical preparation is not required and ARDEX A 38 or ARDEX A 29 screed should be used unbonded.
Once the screed and/or levelling compound is dry, tile as normal using ARDEX X 78,ARDEX X 78 S or ARDEX X 325 PTB Tile Adhesives.