25 Jul Installation of ceramic tile without absorption and stone material on substrates with planimetry defects
In this application we encounter, in addition to the difficulty generated by the low porosity of the coating, the additional problem of executing thick-bed installation.
This type of use is affected by the retraction produced in the mortar joint, due to which it will be necessary to work with adhesives in which this parameter is controlled.
Therefore, the use of a controlled-retraction cementitious adhesive that does not affect the joint between the materials is required.
Preliminary analysis
Having to regularize a surface with the adhesive mortar itself triggers the need to apply a greater thickness than usual.
The consequence of working with these thicknesses is that these adhesives retract during their drying and hardening process, with the ensuing reduced contact between the two surfaces.
Considering that the union between the ceramic and the cementitious adhesive is by contact, this union will be worse the greater the retraction, due to which we must use an adhesive:
- With low or no retraction.
- A flexible adhesive which, to the extent possible, absorbs the movements of the substrates.
- That provides chemical adherence.
- With adequate granulometry, which offers us a structure capable of resisting greater thicknesses than usual.
- Resistant to support the stress produced by the weight of the ceramic (greater stress the greater the distance between the coating and the ceramic).
Technical considerations
In this type of application, different factors must be considered to correctly choose the adhesive and installation system.
Therefore, we must decide:
- Whether the surfaces to be cladded are interiors (suffer less atmospheric aggressions) or exteriors.
- The format of the ceramic to be installed and the substrate is important.
- Before installing the floor, the public or private use thereof must be considered, in addition to the loads it will support (a supermarket is not the same as a car dealer, as a clothes store or a house).
- Once all these options have been analyzed, and taking into account that the union we expect in these materials is only by contact, we must always ensure that the entire surface of the cladding and the substrate is impregnated, without leaving any cavities.
- We must rule out the possibility of executing the application using the spots or gob technique; in this way, the stress would be grouped together in these contact areas, significantly reducing adherence.
- Furthermore, the areas that will remain hollow in the event of pressure will act as levers, lifting the tile in its entirety.
- We recommend spreading the adhesive over the substrate, executing the same operation on the back of the ceramic tile, pressing the tile onto the substrate, packing solidly, until achieving the desired flatness.
A second consideration, but nonetheless essential, to be considered is the design of the joints, making sure to:
- Leave at least 2 mm joint spacing between tiles.
- Execute perimeter movement joints in corners and changes in plane, height or material.
- Execute expansion joints between door and structural cavities of the building.
- All expansion joints should be filled with elastic mastics such as G#color Elastic-MS.
- Jointing mortar must be applied in accordance with the times marked in the Technical Data Sheet of the adhesive.
Commissioning will take place 48 hours after executing the joint.
Recommended products
Adhesives
Joint mortars
Flexible mastic
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 info@gecol.com