What primer to use before tiling?

Priming prepares the substrate to ensure proper tile adhesion and long-term durability. It stabilises the surface and creates the right conditions for the adhesive to perform consistently.

On absorbent substrates, primer regulates suction and prevents the adhesive from drying too quickly. On smooth or dense surfaces, it creates a bonding layer that improves grip where adhesion would otherwise be limited.

It also helps bind fine particles at the surface and supports mookre even curing of the adhesive across the area.

Without this step, issues such as poor bonding, uneven curing, or tile detachment are more likely to occur. Proper priming helps reduce these risks and contributes to a more reliable installation.

For porous surfaces

On porous substrates, controlling absorbency is essential to ensure consistent adhesive performance. Materials such as concrete, cement screed, or anhydrite can draw moisture quickly, which may affect curing if not properly managed.

GRIP A500 MULTI is designed to regulate suction and create stable conditions for adhesive application. It can be used on both standard and highly absorbent substrates, helping to maintain a consistent drying behaviour across the surface.

The product is compatible with tile adhesives and levelling compounds, and can be used in both indoor and outdoor environments. It is typically applied with a roller or brush, depending on site conditions.

Drying time before over-coating is generally between 30 minutes and 3 hours, depending on substrate absorbency, temperature, and humidity. On highly absorbent surfaces, a second coat may be required to achieve uniform coverage and avoid issues such as air bubbles or uneven drying.

With an average consumption of around 75 g/m² and a very low VOC classification (EC1 Plus ¹), it supports efficient application while meeting indoor air quality requirements.

For non-porous surfaces

Smooth and dense substrates require a different approach, as adhesion can be more difficult to achieve. Surfaces such as existing ceramic tiles, terrazzo, synthetic flooring, or certain natural stones offer little to no absorption, which limits the bonding capacity of standard primers.

GRIP A936 XPRESS is designed for these conditions. It creates mechanical grip on the surface, thanks to its quartz content, which forms a textured layer once applied. This makes it particularly suitable for renovation work, where new tiles are installed over existing dense substrates.

The product is applied evenly with a roller, avoiding excess material or puddles. Drying time typically ranges from 30 minutes to 3 hours, depending on ambient conditions and the substrate. Once dry, the surface is ready to receive tile adhesive or a levelling compound.

With its EC1 Plus ¹ classification, it also supports low-emission indoor environments while providing a stable and reliable base for tiling.

When working on surfaces with underfloor heating, specific precautions are required. The system should be switched off at least 48 hours before applying the primer to avoid affecting drying and adhesion.

After installation, the heating should only be restarted gradually, typically after a minimum of 7 days. This helps prevent thermal stress on the freshly applied system and supports proper curing.