INSTALLATION & MAINTENANCE

Natural stone mosaics bring texture, movement, and timeless character to interior spaces. Because these materials are formed by nature, proper installation techniques are essential to ensure both visual beauty and long-term durability.

The following guide outlines best practices for installing natural stone mosaics. All installations should be completed by a qualified tile professional and must follow the current standards established by the Tile Council of North America (TCNA) Handbook for stone tile installation.

Successful installations begin with proper surface preparation. The installation substrate must be clean, flat, stable, and dry prior to setting tile.

Acceptable substrates typically include cement backer board, mortar beds, or properly prepared concrete surfaces. Any dust, oils, or contaminants should be removed to ensure proper adhesion.

Because mosaic installations are made up of small individual pieces, they can highlight irregularities in the substrate. Surfaces should therefore be flattened and leveled prior to installation to prevent unevenness in the finished mosaic surface.

For shower walls, floors, or other wet areas, a properly installed waterproofing membrane should be in
place before tile installation begins, in accordance with TCNA guidelines.

Natural stone exhibits inherent variation in color, veining, and movement. For this reason, a dry layout is strongly recommended prior to installation.

Installers should review and arrange several mosaic sheets together before setting them in mortar. This allows natural variation to be blended across the installation and ensures a balanced appearance.

Maintaining the sheet orientation during installation is also important, particularly for directional or linear mosaic patterns.

Natural stone mosaics should be installed using a high-quality polymer-modified thinset mortar. We recommend the LATICRETE® 254 Platinum, MAPEI® P10, or MAPEI® Kerapoxy 410, which provide reliable adhesion and performance for natural stone applications.

White thinset mortar is recommended when installing natural stone mosaics, as darker mortars may affect the appearance of lighter stones.

Mortar should be mixed according to manufacturer instructions until a smooth, workable consistency is achieved. Using an appropriately sized notched trowel, mortar is spread evenly across the prepared substrate.

For mosaic installations, professionals often flatten the trowel ridges using the flat side of the trowel before placing the mosaic sheets. This helps prevent mortar from pushing through the joints duringinstallation.

Mosaic sheets should then be pressed firmly into the mortar bed using even pressure to ensure full contact with the substrate.

Mesh-mounted mosaic sheets are designed to simplify installation while maintaining consistent spacing between individual stones.

Sheets should be aligned carefully and pressed into place while maintaining consistent joint spacing between adjacent sheets. A grout float or beating block can be used to gently tap sheets into alignment and ensure a flat surface.

Excess mortar that rises into the grout joints should be removed before it cures.

Because mosaic patterns can be intricate, adjustments may occasionally be required during installation. Individual pieces may be repositioned or trimmed as needed using mosaic nippers or a tile wet saw.

After installation, allow the thinset mortar to fully cure according to manufacturer recommendations before proceeding to grouting.

Once the mortar has cured, grout is applied to fill the joints between the stone pieces. We recommend using LATICRETE® Permacolor grout or MAPEI® Ultracolor grout, which provide excellent performance and color consistency.

Grout should be spread diagonally across the mosaic surface using a rubber float, ensuring the joints are completely filled. Excess grout is then removed from the surface before the grout begins to firm.

A damp sponge is used to clean the surface and remove grout haze during the initial cleaning stage. A final wipe may be performed once the grout has set.

Proper curing time should be observed before sealing the installation.

Changes of plane and movement joints should not be filled with grout. These areas must be treated with a flexible sealant to accommodate structural movement.

Typical locations for movement joints include:

• Wall-to-wall intersections
• Wall-to-floor transitions
• Corners and perimeter edges

For these applications, we recommend LATICRETE® Premium Acrylic Caulk or MAPEI® Keracaulk U®. Flexible sealants help maintain the integrity of the installation while preserving a clean finished appearance.

Movement joint placement should follow the recommendations outlined in the TCNA Handbook.

Natural stone is porous and should be sealed to help protect the material from staining and moisture absorption.

After the grout has fully cured, a penetrating sealer such as STAIN-PROOF® sealer should be applied to both the stone surface and grout joints. STAIN-PROOF® sealer is available through our shop for convenient purchase alongside your mosaic selection.

Penetrating sealers work below the surface to protect the stone while maintaining its natural appearance.

Depending on the stone type and level of porosity, multiple coats may be recommended. Always follow the sealer manufacturer’s instructions during application.

Routine cleaning is important to preserve the beauty of natural stone mosaics.

We recommend using FILA® pH-neutral stone cleaner, which is specifically formulated for natural stone surfaces. These cleaners safely remove everyday dirt and residue without damaging the stone or the protective sealer. FILA® cleaner is also available through our shop to help maintain the beauty and longevity of your installation.

Avoid acidic, abrasive, or harsh chemical cleaners, as these products may damage or etch certain natural stone materials.

• Natural stone mosaics should always be installed by experienced tile professionals.
• Dry layout of sheets is recommended to ensure natural variation is blended properly.
• White thinset mortar is recommended for most natural stone installations.
• Seal stone and grout after installation to help protect against staining.
• Always follow current TCNA Handbook guidelines and manufacturer instructions for setting materials.

Natural stone is a product of nature and will exhibit variation in color, veining, texture, and movement. These characteristics are part of the inherent beauty of the material and contribute to the uniqueness of every installation.

Because of this variation, reviewing physical samples and laying out multiple sheets prior to installation is strongly recommended.

Laticrete 254 Platinum: https://www.laticrete.com/products/254-platinum

Mapei P10: https://www.mapei.com/us/en-us/products-and-solutions/products/detail/adesilex-p10-mosaic-glass-tile

Mapei Kerapoxy 410: https://www.mapei.com/us/en-us/products-and-solutions/products/detail/kerapoxy-410

Laticrete Permacolor Grout: https://www.laticrete.com/products/permacolor-grout

Mapei Ultracolor Grout: https://www.mapei.com/sg/en/products-and-solutions/products/detail/ultracolor-plus

Laticrete Acrylic Caulk: https://www.laticrete.com/products/premium-acrylic-caulk

Mapei Keracaulk U: https://www.mapei.com/ca/en-ca/products-and-solutions/products/detail/keracaulk-u