Suelo sobre baldosas antiguas | Revestimiento cerámico

Installation of ceramic tile over an existing tile substrate

The installation of ceramic on traditional substrates is not always necessary (e.g.: cement mortar).

At times, certain refurbishing work requires installing ceramic over an existing substrate of similar nature.

In this manner, we achieve greater convenience and cleanliness on not generating rubble and speed of execution, as we avoid having to remove the existing floor.

Preliminary analysis

Normally, these old tiled floors are dirty (greases deposited on the surface and on the joints). They are non-porous substrates (normally varnished) and can be found in places with a certain degree of relative humidity (bathrooms, kitchens, etc.).

For all these reasons, we will need an adhesive that is:

  • Deformable, with perfect adaptation between the varnished substrate and the new ceramic piece.
  • Resistant to relative humidity and condensations.

Technical considerations

The first consideration to be taken into account is the state of the substrate on which the cladding will be installed:

  • We must verify the stability of the existing tile floor, which must be resistant, clean, dry and perfectly anchored.

We must ensure that the existing tile floor is well adhered. Otherwise, remove loose tiles, fill any cavities with a specific mortar such as GECOL Sec or GECOL Revoco base and let dry for 12 to 24 hours.

Clean the surface to remove all traces of residue (waxes, greases, etc.) and let dry completely.

  • Open the pores by washing with GECOL Desincrustante, diluted with water in the ratio 1:3 and afterwards rinse with clean water.


A second consideration to be taken into account is the design of the joints, verifying the existence of:

  • 3 mm joint spacing between tiles.
  • Perimeter movement joints in corners and changes in plane, height or material.
  • Building structural joints.


All expansion joints should be filled with elastic mastics such as G#color Elastic-MS.

Likewise, the use of mechanical anchorages is obligatory whenever tiles with dimensions greater than 60 x 40 cm or 40 kg / m2 are installed.

Jointing mortar must be applied at least 48 hours after installing the floor.

Commissioning will take place at least 48 hours after executing the joint.

Recommended products



Anhydrite supports

High performance

Ultra-fast setting

High deformability

Joint mortars

From 0 to 20 mm quick setting

From 3 to 15 mm

Completely watertight joints

From 2 to 15 mm

Flexible mastic

Elastomeric mastic


Masonry mortar



Acid cleaner

Warnings: The data provided by this Constructive Solution were prepared based on standard onsite installation processes. However, we recommend that you consult our Technical Department in the event of any specific circumstance