Fixing ceramic tiles on fresh mortar

Thick layer flooring using the traditional method has its risks, due to the evolution of ceramics towards low absorption types.

The adherence of the layer of fresh mortar to low absorption tiles is not sufficient, and the tiles can work loose.

The large formats have bends or curvatures of their own manufacture, which makes difficult the contact with the support.

The technique of wetting the surfacing after fixing the tiles, does nothing to improve their adherence to the layer of fresh mortar, due to their poor porosity.

Solution

PREPARING THE SUPPORT

Regularization of mortar coating will take place with PROPAM® RECRECIDO PRONTO, PROPAM® RECRECIDO PRONTO PLUS, or mortar
M-7,5 silíceo and it must be cool to be able to apply VAT® TAC.

APPLICATION

By scattering, for tiles smaller than 900 cm². Apply by scattering an even layer of 1 to 2 mm of VAT® TAC directly onto the plate of fresh mortar, without any excess or overlooked parts.

Then dampen the product with water before fixing the tiles.

By barbatine, for tiles larger than 900 cm². Mix VAT® TAC with a slow electric mixer (500 rpm) and leave to stand for 1 minute, mix again until a smooth paste is formed to be used and spread over the support using a trowel or palette.

Fix the tiles and press them until they form a perfectly solid surface.

Leave a minimum grouting joint (width of 2 mm indoors, and 5 mm outdoors); regrout with the grouting range BORADA® by PROPAMSA when the adhesive mortar has dried completely.

Recommendations

Do not apply in wet weather, or with temperatures of <5ºC or >30ºC.
The wind reduces the adhesive´s open time and leads to reduced adherence.
When the tile size is over 900 cm² or with a rib larger than 3 mm, fix the tiles using the Floating and buttering method.
On outdoor floors the inclination angle of the support must be equivalent to or more than 1% to allow water to be removed.
Do not use in conditions where there is a risk of water stagnating.
Treat the movement joints appropriately, respecting the structural joints, perimeter joints (in those places where the surface to be tiled is interrupted by elements such as walls, columns, different levels,…) and intermediate joints (indoors every 40 m² and outdoors every 10 to 25 m²).