Installation Guide: Marble

Preparation

Prior to installation of Natural Marble:

• Open and inspect all marble cartons.
• All cartons should be opened, and material should be separated to allow the installer to layout all pieces and blend them together to give the final installation a uniform color blend, known as "Dry Laid."
• On large jobs, blend material from multiple pallets during Dry Laying.
• When laying out the installation, DO NOT set marble with a "Butt Joint"; Tile Council of North America suggests a minimum 1/16” grout joint.
• For grout joints 1/16”- 1/8” width, use Unsanded Grout.
• For grout joints 1/8”- 5/8" width, use Sanded Grout.

Installation

When installing Natural Marble:

• Use a white thinset when installing any light-colored natural stone.
• Using grey thinset could show trowel ridges or shading through the marble, affecting the finished installation color of natural stones.
• On natural marble with fiberglass backs, always use a quality Latex Modified Thinset to ensure proper adhesion to the fiber back.
• Many manufacturers recommend using latex modified thinset for marble rather than mastics, which may stain and discolor many natural stones.
• Always follow manufacturers' Limitations and Instructions.
• Test for compatibility.
• When used in showers or tubs, Marble should never be set with the bottom course extending into the shower base or tight to tub lip. Always leave a minimum gap of 1/4” above and perpendicular to the floor or lip of the tub or shower base and use a waterproof flexible sealant where they meet per TCNA specification B412-23.
• This prevents water from wicking up the body of the marble, preventing discoloration.
• For marble shower floors, recommend installations that incorporate a Complete Water Management System (e.g., Bonded Waterproof Tiled Shower Assemblies - Schluter) vs. Traditional shower installations (Mud job).

Grouting

Grouting Natural Marble:

• The use of sanded grouts may cause scratching of polished or high honed marble.
• When using sanded grout, always conduct a test sample first.
• The use of products like Aqua Mix's Grout Release or pre-sealing marble prior to grouting helps prevent pigments in grout colors from staining natural stone.
• Pre-sealing makes for easier installation cleanup of grout residue.
• When using High-Performance grouts, ones which don't require that the joint be sealed, natural stone should be pre-sealed prior to grouting with 2 coats of products like Aqua Mix's Sealers Choice, Enrich n Seal or Grout Release. This will minimize the polymers in the grouts from discoloring the natural stone.
• When using Epoxy, Urethane, Sanded or Unsanded grout, always conduct a test sample first to determine compatibility with the stone.

Sealing

Sealing Natural Marble and Grout Joints after installation regardless of the finish:

• Always use a high-quality penetrating sealer like Aqua Mix® Sealers Choice® Gold to maintain the stone's natural color or a high-quality color-enhancing penetrating sealer like Aqua Mix® Enrich ‘N’ Seal™ to enhance the natural color of the stone.
• When sealing natural marble, apply each coat in a different direction (e.g., first coat Left to Right, Second coat Front to Back).
• Multi-sided or 6-sided sealing of material 48 hours before installation will help minimize darkening of Marble on shower floors caused by water absorption and reduce the formation of effervescence and rust.
• Use on material in areas with excessive moisture exposure: shower floors, marble walls along the base of the shower or tub flange, soap niches.
• As per National Tile Contractors Association Reference Manual, Custom, or Mapei technical articles.

Common Problems in Natural Marble

Stain Removal:

• Sealing marble will help reduce staining.
• Always clean up spills promptly.
• Minor stains occurring in natural marble after installation can be removed using a Product like Aqua Mix® Poultice Stain Remover per the manufacturer's directions.

Etching in natural stone:

• Sealing marble after installation will help minimize etching.
• Enhancing Sealers may help hide the dullness of some etched stones, but professional repolishing may be required to eliminate it.

Other Issues:

• Lippage or uneven surface height issues are often a result of improper installation.
• Always inspect material for uniform thickness before installation.
• Recycled or discolored water in wet saws trays and cleaning water can permanently stain natural stone.
• Many natural stones tend to be extremely porous prior to sealing, Elon® recommends that all water being used to cut or drill natural stone be kept fresh and clean.
• Elon® suggests a separate clean container of fresh non-recycled water be used in all wet saws and drills when working with natural stone.