Adhesive, Joints and Spacers

Installation Materials: Adhesive, Grout and Spacers for Cement Tiles

The success of a decorating project doesn't end with selecting the pattern or color of your tiles. It lies just as much in the quality of the installation and the careful choice of installation materials. This collection of adhesives, grouts, and spacers was designed by the Carocim technical team to offer you the most suitable solutions for our exceptional products. Because our cement tiles, handcrafted in our workshops, deserve special attention, it is essential to use a high-performance adhesive, appropriate grout, and precise spacers. Entering the technical world of tile installation may seem complex, but it ensures greater longevity for your floors and walls. Whether you are a seasoned professional or a passionate homeowner, understanding the interaction between the adhesive, the substrate, and the tile is the first step toward a successful project. Here, we will explain why choosing the right adhesive is vital, how to achieve perfect grout lines, and the benefits of modern spacers.

The strategic choice of tile adhesive for cement

Cement tiles are a "living" surface covering, composed of marble powder and cement, unfired but pressed. This unique characteristic requires an adhesive with very specific properties. A standard, inexpensive adhesive is insufficient for installing such high-quality materials. The density of our tiles (16 mm for flooring) results in a significant weight, necessitating a high-adhesion adhesive.

Why is it absolutely necessary to choose white glue?

It's a golden rule at Carocim: using white adhesive is practically mandatory. Unlike glazed porcelain stoneware, which is impermeable, cement tiles have a natural porosity on their underside. If you use a standard gray adhesive, there's a real risk that the dark pigments will wick up to the tile surface during installation, or that they will show through slightly, dulling the vibrancy of the colors. A white adhesive, or a white tile mortar, ensures the neutrality of the substrate and preserves the brightness of your designs.

Adhesive flexibility: C2S1 standards

Modern home floors are subject to stresses: vibrations, expansion due to underfloor heating, and natural building movement. A rigid adhesive will eventually break under these stresses, causing tiles to detach. We recommend a C2S1 certified (flexible) adhesive suitable for small areas. This designation on the adhesive bag means that the hardened mortar retains a certain degree of flexibility. The C1 classification designates standard tile adhesives, while the C2 classification represents improved adhesives. This elasticity allows the adhesive to absorb thermal and mechanical shocks without breaking the bond between the substrate and the tile. This is particularly crucial if you are installing tiles over underfloor heating, where the adhesive must withstand heating and cooling cycles without cracking, or if you are renovating an older home with slightly shifting floors.

The art of grouting: more than just a finishing touch

While the adhesive ensures mechanical strength, the grout provides waterproofing and visual harmony to the surface. Tile joints are not simply filled gaps; they contribute to the overall structure of the floor by allowing it to "breathe." For Carocim cement tiles, grouting requires great care and adherence to specific DTU (Unified Technical Document) standards.

What joint width should be used?

The DTU (Unified Technical Document) standards recommend minimum joint widths to prevent structural problems. For our tiles, which are handcrafted and may have very slight dimensional variations, we advise a thin but technically sound joint. A 2 to 3 mm joint is ideal. It compensates for micro-differences in tile size while remaining visually discreet. Attempting to create excessively thin joints (less than 2 mm) with handcrafted tiles requires considerable skill during installation to avoid irregularities. Conversely, excessively wide joints detract from the pattern, especially if you are creating a complex decorative pattern.

Grout color: a question of balance

The choice of grout color is just as important as the color of the tile itself. Absolutely avoid black grout with light or colored tiles, as cleaning off excess black grout could irreversibly stain the porous marble powder before the waterproofing treatment. Choose your grout from our range of colors. These grout colors blend naturally with the mineral composition of the cement tile. During application, be sure to quickly clean off any excess grout with a sponge to prevent the formation of a stubborn cement residue (laitance) on the delicate tile surface.

Cross braces: ensuring regularity and flatness

To achieve perfect alignment and consistent joint width, the use of tile spacers is essential. However, in the world of modern tiling, not all spacers are created equal, and their function has evolved.

Standard cross braces or self-leveling systems?

Traditional cross spacers are very effective for managing horizontal spacing. However, to ensure perfect flatness (no unevenness or "lip" between two tiles), self-leveling spacer systems (often consisting of a dial, a rod, and a wedge) have become the standard among demanding professionals. These spacers allow, when tightened, the two adjacent tiles to be perfectly level while the adhesive dries. However, be careful: with handmade cement tiles, the thickness can vary by a few tenths of a millimeter. Self-leveling spacers must therefore be used gently to avoid putting excessive force on a tile. The spacer should help with flatness, not constrain the material. Proper use of self-leveling spacers guarantees a smooth, pleasant-to-the-touch floor where you don't trip on edges when walking.

The installation technique: Preparation and Double Bonding

Having the right adhesive, grout, and spacers isn't enough if the installation technique isn't suited to the material. The best technique for laying large-format or thick tiles like ours (16mm) is double-bonding.

Why is double gluing non-negotiable?

Single-bonding involves spreading the adhesive only on the floor using a notched trowel. For a 16 mm thick cement tile, which is heavy and dense, this is technically insufficient. Double-bonding is absolutely necessary.

• Apply the adhesive to the substrate (the screed) with a wide-toothed comb (U9 or half-moon) to create a regular bed.
• Apply a thin layer of glue (buttering) to the back of the tile with the flat side of the trowel, and place it perpendicular to the previous one.

This technique ensures complete adhesive transfer between the floor and the tile. It eliminates air pockets beneath the tile that could create weak points. Without double-bonding, the tile risks sounding hollow and cracking when a heavy object is dropped on it, as it is not supported by the adhesive across its entire surface. While adhesive consumption will be higher (approximately 5 to 6 kg per square meter), this is the price of durability and mechanical strength.

The importance of preparing the substrate

Before even opening your first bag of adhesive, carefully check your substrate. It must be clean, dry, sound, and level. If the screed has significant irregularities, a leveling compound is necessary beforehand. Adhesive can compensate for minor leveling defects, but it is not designed to level the floor over large differences. On highly absorbent substrates (plaster, anhydrite screed, old porous cement screed), applying a bonding primer before applying the adhesive is recommended. This primer regulates porosity and prevents the substrate from absorbing the adhesive's mixing water too quickly, which would compromise its chemical setting and final adhesion.

The tools of a tiler: the essentials for success

To use this technical adhesive and these thin grout lines, you'll need the right tools. In addition to tile spacers, you'll need a good quality electric mixer. Mixing the adhesive by hand is tedious and often produces a lumpy, uneven mixture. Poorly mixed adhesive loses much of its mechanical properties and open time. Use a notched trowel appropriate for the tile size. For our standard 20x20 cm tiles, a U9 or U10 trowel is often recommended for the adhesive bed on the floor. For grouting, a soft rubber float is necessary to work the mortar into the gaps without scratching the tile surface (which is softer than glazed ceramic). Finally, clean the grout with a dense, absorbent tile sponge and a tray of clean water that is frequently changed to avoid redepositing the grout on the tile.

Maintaining your installation after installation

Once the adhesive has dried (generally allow 24 to 48 hours before walking on it, depending on the adhesive's technical specifications) and the grouting is complete, the project isn't quite finished. The crucial final cleaning stage remains, removing the cement residue (laitance) and any remaining adhesive. Caution: never use pure hydrochloric acid or harsh chemicals on cement tiles! This will immediately damage the limestone in the marble dust used in the design. Use specific, gentle cleaners ("laitance remover for natural stone") available in our maintenance range. The aesthetic durability of your grout will also depend on this initial thorough cleaning. Clean, healthy grout contributes to the overall look of the room. Next, apply the second coat of water- and oil-repellent treatment, which will protect both the tile and the grout from everyday stains, sealing your work for decades to come.