WALL TILES / FLOOR TILES INSTALLATION
Proper placement will not only enhance the beauty of the tile but will also ensure its durability by preventing possible detachment or breakage.
Just as certain features are required of ceramic tiles, it is common sense that these requirements be extended to construction professionals, so that the execution of each work is carried out according to their particularities and requirements, preventing In addition to proper placement, the use of the most suitable bonding materials for the various types of tiles and environments, thus enhancing the beauty of the flooring and ensuring its durability.
Our recommendations are grouped into:
1. Wall & Floor Tiles
2. Placement and Deformation Joints
The function of the bonding materials is to guarantee the correct bonding of the ceramic to the support. Therefore, the final finish of the installation will largely depend on the proper selection and use of the bonding material.
Porous single-fired wall tiles in large and medium formats must be laid in a thin layer with adhesive cement with polymeric additives. In small formats, traditional thick layer mortars can be used. If the cladding is intended for plating bathrooms or places with direct exposure to water, it is necessary to use waterproof and watertight installation joints.
Nature and condition of the supports: The planning and execution of the work must include a correct conception and preparation and execution of the base support (normally slabs and concrete floors), of the intermediate layers (regularization layer, thermal and acoustic insulation, waterproofing or radiant heating) and the installation surface, which must be compatible with the bonding materials to be used. To guarantee the durability of the walls, the following factors must be taken into account: Use of cement-based supports, well dosed and cured (the drying and hardening times must be respected), resistant to water, and that prevent the capillary rise of humidity from the underground. A wet support is unstable and can cause adhesion problems, as well as warping and shrinkage that can cause the tiles to crack or lift over time.
• When working on thermal or acoustic insulation, we must know what behavior is expected of these materials with respect to the ceramic installation system, since in general, installation supports that have intermediate layers have unstable behavior, and it is advisable to prepare a compression layer that allows the distribution of loads.
• In order to achieve good adhesion to the installation surface, its genuine and firm surface must be discovered, for which it will be necessary to proceed to an exhaustive cleaning. The existence of residues in the form of dust, grease, paint, efflorescence, grout, traces of plaster, etc., weaken the adherence.
• Due to the fact that the performance of adhesive mortars is reduced from a thickness of 5 mm, laying in a thin layer does not allow unevenness in the support to be corrected with excess adhesive, which is why it is essential to have perfectly flat surfaces. However, there are adhesives that allow placement in the middle layer with thicknesses of up to 15 mm, which would allow us to correct planarity deviations of 10 mm measured with a 2 m ruler.
• If we find larger deviations, it would be convenient to apply a leveling layer to correct them. The certainty that the pavement will only reproduce each and every one of the irregularities that the support manifests must be weighed before ignoring this premise.
• The roughness of the surfaces to be glued contributes to enhance adhesion by mechanical anchoring. For this reason, it is advisable to mechanically alter excessively smooth supports such as vibrated concrete, precast concrete, or the leveling layer itself.
Laying this flooring requires the thin layer laying technique and the use of gripping materials appropriate to its characteristics (see CE Marking). As a general rule, the use of C2-type Cementitious Adhesives is recommended, according to the specifications of the European standard EN 12.004 “Adhesives for ceramic tiles. Definitions and specifications”. To achieve a good grip and a long duration, the following factors must be taken into account:
• Strictly follow the manufacturer's recommendations in the preparation of the adhesives.
• Prepare the mixture using mechanical beating elements, so that a homogeneous product without lumps is achieved.
• Double-glued placement (both on the support and on the piece) guarantees perfect adhesion to ceramic pieces and prevents gaps from forming between them and the support.
• The “combing” of the glue on the support, with a notched trowel of suitable tooth size, ensures a regular thickness and a good distribution of the glue over the entire surface.
• Once placed, an energetic shake will be carried out piece by piece, so that a good settlement is achieved. Periodically placed pieces will be lifted to check the perfect solidity of the adhesive.
It must be taken into account that the base support is usually a continuous surface subject to contractions and expansions caused by thermal changes, structural movements, the effects of water or humidity, chemical reactions, or the shrinkage of the cement itself. For this reason, a perfect execution of the joints guarantees that these natural movements of the base support are not transferred to the tiled surface.
The dimensioning of the structural joints must be perfectly detailed in the building project, and must be set by the architect or specialized engineer. They are placed in correspondence to the structural joints that are constructively necessary. They are usually finished off by filling them with materials of lasting elasticity.
Their mission is to isolate the ceramic flooring, together with its corresponding layer of adhesive, from other coated or paved surfaces such as wall-floor joints or joints with other construction elements such as pillars, window frames or doors. Its mission is to prevent both the ceramic material and the adhesive from coming into contact with the aforementioned elements, in order to prevent the accumulation of stresses. The joints between walls and floors are always necessary for surfaces greater than 7 m2. A joint width of 5 to 10 mm is recommended, which will be hidden by the skirting board, or by the adjacent cladding. The perimeter joints must be suitably executed and function as such, that is, they must be clean of remains of building materials and reach the slip layer, base support, or asphalt fabric, so they must be planned before placing the layer of regularization or else it will be impossible to execute them correctly. The analysis of the most common pathologies reveals that the poor execution or omission of the perimeter joints is one of the most frequent causes of tiling removal.
They are intended to allow differential deformations caused by thermal and hygroscopic variations between the tiles, the adhesive layer, and the support. The design of expansion joints is usually carried out on site, so it may be useful to have some minimum criteria for their dimensioning, such as the following:
• The minimum width will be 5 mm, being usually 8 mm.
• It is advisable to divide the installation surfaces into panels whose areas do not exceed 50 -70 m2 in interior environments.
• They must also be placed interrupting linear dimensions that exceed 8 m.
• Expansion joints must be suitably executed and function as such, that is, they must be
flexible, waterproof, well adhered and must reach the slip layer, base support, or asphalt fabric.
• They can be filled with profiles or elastic materials.
• Tile joints perform an important aesthetic function, enhancing the beauty of ceramic tiles and compensating for small dimensional variations. They imply the mutual separation regularly repeated between the individual tiles, recommending the use of spacers and wedges to achieve a perfect alignment of the tiles and the constancy of the thickness of the joints.