Tile-over-tile installation with a supplementary screed on a historic screed.

Structure type

Screed with existing ceramic, terracotta or stone tiles in good condition that are not to be removed.

Detail

Installation of the new terracotta, ceramic or stone flooring with natural hydraulic lime NHL 3.5 adhesive on a natural hydraulic lime NHL 3.5 supplementary screed to make up the floor levels.

Application cycle

1. Lime and sand and/or cocciopesto screed, bonded or floating.
2. Existing tiles, well bonded to the screed, that are not to be removed.
3. RALLK UltraLevel Kalce build-up layer based on NHL 3.5 natural hydraulic lime, 3 to 30 mm thick, laid at least 24 hours after spraying or brushing RALLK Primer K acrylic bonding primer onto the existing tiles.
4. RALLK Kerasiv Kalce adhesive based on NHL 3.5 natural hydraulic lime for laying terracotta, ceramic or stone tiles indoors or outdoors, in small or large formats.
5. New terracotta, ceramic or stone finish covering.

Additional information

1. On smooth or glazed existing tiles, roughen the surface with abrasive brushes and remove all dust before continuing with the system shown.
2. The build-up layer and the new ceramic or stone covering must be kept away from the perimeter walls with expanded PE strips, so that they do not butt against the plaster.
3. Avoid drafts in the rooms by keeping windows and doors closed for the first 24-48 hours after laying the build-up layer.
4. See the individual product data sheets for application methods and precautions.