Stone Mosaic Installation Guide

PREPARE FOR INSTALLATION
1. Set the mosaic on a substrate that is rated to hold natural stone. This will include cement backer boards, concrete masonry units, brick/masonry, exterior grade plywood, traditional mud beds, etc. Consult a professional builder for rating requirements before starting the project.
2. Insure the framing is structurally sound and up to code.
3. Be sure the entire surface is level before installation.
4. All surfaces must be sound, clean, and free of oil, waxes, frost, curing agents, form release agents and any other bond inhibiting contaminants. After the surface is completely clean, inspect the surface for any dips or bumps. Make all repairs necessary to make the surface level and smooth.
5. Before you begin, insure that whatever type of setting materials used are rated to hold the types of stone mosaic being used. Be sure to use non-staining setting materials and follow the package instructions to make it ready to be troweled onto the surface.
 

SET THE MOSAIC
1. Using no larger than a 1/4” x 1/4” inch “V” notched trowel (a 3/16 “V” notch is usually perfect) or one suggested for the setting materials used, trowel out enough mortar or adhesive to cover the area to set the first few sections. When troweling the mortar out be sure that it is spread evenly. Thick spots will result in mortar to bleed up through the grout seams that will then have to be picked out below the surface before grouting. Thin spots will result in stone mosaics not sticking at all.
2. Carefully place the first two to four sections (MESH SIDE DOWN) into place. Using a level surface and a rubber mallet, tap the sections into the setting material, avoiding the outside edges adjacent to the next sections. Then press the next sections into the setting material, making sure to match the width of the established grout lines. Doing so will prevent the seams from showing. Use the grout space between the stone mosaics within the section of mosaic as your guide for spacing. Tap again with your flat level surface, this time pressing down on the seams between sections (this avoids “cupping”), but again avoiding the outside abutting edges (except for the edges that are against the outside wall or threshold).
3. Repeat step (4) on the next few sections. Periodically examine installation. If the seams are undetectable, the job has been done well. Seams are created by gaps in section placement, uneven (height) pieces along the edge of the seam, and stone mosaic not lining up within a section, etc. The seams will need to be re-worked between the sections as necessary to make them undetectable. To rework seams reset pieces on the seam to blend them in. Repeat steps (4) and (5) until the mosaics are entirely set and seamless. Follow the instructions on the setting material package; do not walk on the surface of the stone mosaic for 24 to 36 hours depending on the type of setting materials used.

GROUT THE MOSAIC:
1. Choose a grout color appropriate for the installation. Mix grout according to manufacturer’s directions.
2. Grout openings between tiles and sheets.
3. Clean the joints with a damp sponge taking care not to remove too much grout. A powder residue will appear. Buff this with a soft dry cloth.
4. If grout dust still remains on the tiles, use water and rinse repeatedly until dust is gone.
5. After grouting, protect area from foot traffic and water exposure for at least 72 hours.