TECHNICAL SOLUTIONS
Recommendations
for the Installation of Ceramic Products
Installation Technique
Adhesion, considered as the bonding strength between the ceramic piece and the substrate, plays a crucial role in the quality of the ceramic tile. Good adhesion must ensure a firm attachment of the pieces to the substrate. The evolution of new ceramic materials with low porosity, resistance to abrasion, frost, large formats, as well as their installation in industries, large commercial areas, facades, etc., necessitates the development of adhesive products.
The knowledge acquired about the use of special adhesives has led to the replacement of the thick-layer installation process (mechanical adhesion) with a thin-layer installation system (chemical adhesion), which offers clear advantages, especially related to the quality of the work, both in terms of adhesion and durability. Therefore, an appropriate adhesive should be chosen based on the installation surface and the type of ceramic tile.
It is very important that suitable tools and equipment (notched trowel, white rubber mallet, bubble level, and suction cup) are used in the installation of the ceramic tile. It is also crucial to ensure that the installation substrate or base is very clean, free of any stains, plaster residue, paint, etc., so that the adhesion can perform its functions over time.
Always follow the adhesive manufacturer’s instructions.
Movement Joints
For a correct installation of ceramic products, it is always necessary to respect the movement joints: structural, perimeter, expansion, and installation joints.
Perimeter joints
These must always be respected as detailed in the project, set by the specialized engineer or architect.
Partition joints
These must be continuous and their width should not be less than 8 mm. Their function is to isolate the ceramic flooring from other coated surfaces such as wall-floor intersections (hidden by the skirting board), pillars, and doors.
Omitting perimeter joints is one of the most frequent causes of ceramic tile lifting.
Partition joints
These allow for existing deformations caused by thermal variations between the tiles, the layer, and the substrate. Large support surfaces covered with ceramic products should be subdivided into smaller areas, delimited by partition joints, whose function is to prevent the accumulation of expansions and contractions. In floors subjected to heavy pedestrian traffic, hard wheel traffic, or heavy load dragging, it is necessary to use specific partition joints suitable for heavy loads.
Installation joints
For safety against any structural movement (expansion-contraction), it is always necessary to place a separation joint, which will be left between
all contiguous ceramic tiles. It is recommended not to place the tiles with a separation of less than 2/3 mm. The advantages of installation joints are several: they help absorb deformations caused by the substrate and moderate the stresses generated on their lower part when subjected to loads. Accumulated stresses can lead to the lifting of the tiles. They also have an important aesthetic function, enhancing the inherent beauty of the ceramic. The joints can be finished flat, flush with the tiles, or concave and recessed.
Their application field includes both interior and exterior coatings. There are also low-porosity, deformable, and waterproof joint sealants available, suitable for facades, pavements subjected to heavy traffic, and premises with persistent water presence. For locations frequently exposed to acids and alkalis in food or sanitary environments, it is necessary to use base sealers; reactive two-component resins such as epoxy sealers. This type of grouting material is characterized by its composition based on synthetic resins (generally epoxy resin). Its main properties are: resistance to chemicals, bacteriological resistance, very good moisture resistance, and excellent abrasion resistance.
Always follow the adhesive manufacturer’s instructions.
The minimum spacing between the product should not be less than 2-3 mm for interiors and 3-5 mm for exteriors.
Classification of sealers according to EN 13888 standard:
MODIFIED CEMENT-BASED SEALERS CG2
Optional ArW (high abrasion resistance and low water absorption)
REACTIVE RESIN-BASED SEALERS RG
Generally two-component, epoxy-based, resistant to chemicals, completely waterproof, and highly resistant to compression.
Do not use placement joints whose composition contains micronized carbon (carbon black); they should always be avoided.
Adhesive Material
Two types of techniques must be considered for ceramic product installation: thick layer and thin layer.
It is important to emphasize that the installation of porcelain stoneware requires the surface to be completely level and free of substances that prevent proper adhesion. It should always be done in a thin layer, using a notched trowel, a white rubber mallet, a bubble level, and a suction cup. For outdoor applications and formats larger than 900 cm², the double-bonding technique should be used, meaning the adhesive product is applied to both the substrate and the back of the tile.
Always follow the adhesive manufacturer’s instructions.
Thick Layer Installation
This is the traditional technique. The ceramic is placed directly on the substrate (wall, brick, concrete, or sand-cement screed). This technique (thick layer) is more economical and also allows for the compensation of greater flatness defects. For thick layer installation, traditional mortar is used.
Thin Layer Installation (with Adhesives)
This is a more recent technique, adapted to current ceramic materials and the diversity of substrates.
Installation is generally carried out over a preliminary layer that levels the substrate, whether it be plaster on walls or mortar bases on floors.
The advantages of this technique are clear, as it is suitable for any type of ceramic tile and compatible with any substrate. There are adhesives appropriate for each type of substrate and ceramic to be installed. It has a high adjustment time, absorbs substrate deformability, and develops greater adhesion. For thin layer installation, cement-based adhesives, adhesive pastes, and reactive resin adhesives are used. The following types of tile adhesives are considered, depending on the characteristics of the ceramic product to be installed.
Adhesives
Adhesives are classified according to EN 12004 and 12002 standards, which define their adhesion and deformability.
Cement-Based Adhesives C2
Modified Cement-Based Adhesives
Dispersion Adhesives D2
Modified Dispersion Adhesives
Reaction Adhesives R2
Reaction Resin-Based Adhesives
Use and Maintenance of Porcelain Stoneware
Due to the low porosity of porcelain stoneware, it is practically impervious to staining. However, some strongly coloring products may spill or come into accidental contact with the surface, especially polished and semi-polished porcelain. If such substances remain on the surface for some time, staining may occur, so it is recommended to clean them as soon as possible.
Once the installation and grouting operations are completed, the surface of the ceramic material often has residual cement in the form of a film or small accumulations. To remove these residues, cleaning with a diluted acidic solution is usually sufficient in most cases.
Precautions to Consider
- Never perform an acidic cleaning on newly installed ceramic products: Acid reacts with uncured cement, which can damage the joints or deposit insoluble compounds on the surface.
- It is advisable to impregnate the surface with clean water before any chemical treatment (placement joints).
- Regular maintenance involves periodic cleaning by washing with water and a diluted ammonia-based detergent solution.
- For extraordinary cleaning of stains and encrustations that penetrate the surface and cannot be removed by usual cleaning operations, it is recommended to test the effect on an uninstalled tile before attempting to remove a stain with a vigorous procedure. This prevents chemical degradations that could further deteriorate the product’s condition.
Follow the Manufacturer's Instructions
- Do not use metal spatulas or abrasive scouring pads.
- After installation, it is necessary to adequately protect the flooring with cardboard, a layer of sawdust, or another product to prevent potential damage from subsequent work.
- To avoid breakages and any undesired cut finishes, it is advisable to use appropriate tools for cutting and drilling porcelain stoneware.
- For straight cuts, use a manual cutting machine with a tungsten carbide wheel (Rodel de Widia), a water-cooled diamond disc machine, and/or a low-power angle grinder equipped with a continuous diamond disc (not segmented).
- For drilling porcelain stoneware, use a diamond drill bit and periodically cool the drilling area with water to avoid increasing the temperature and melting the drill bit.
Installation Tips for Rectangular Products
Do not install the flooring with a staggered layout where the displacement exceeds 14 cm.
Staggered Installation
(between 2-20 cm)
Regular Installation at Half the Piece
(NOT RECOMMENDED)
Leveling Systems
CHIPPING OF GLAZE IN RECTIFIED TILES
When discussing coverings and installation systems, the following considerations should be taken into account:
- Materials in Absorption Group BIII, with absorption greater than 10%.
- More fragile.
- Rectified tiles have a micro-bevel or minimal bevel.
The problem lies in the fact that the edge of these pieces is very delicate, and any small pressure can cause the edge to chip.
Traditional System
In these systems, the wedges are in direct contact with the ceramic tiles, and applying pressure can cause chipping. This happens because when tightening the wedge, pressure is exerted, causing the spacer to tilt to less than 90°, thereby pressing against the tile’s edge.
Leveling System Protector
- Specially designed to protect tiles, especially delicate and thin ceramics.
- The protector is placed under the wedge to achieve a flawless finish of the flooring or tiling, reducing friction between the wedge, spacer, and ceramic tile.
USE OF THE PROTECTOR
