We provide these natural stone tile and mosaic installation instructions as a supplemental, general installation and grouting guideline only, as it pertains to most applications. The technical service departments of setting material manufacturers should be consulted regarding specific installation and material use questions.
All natural stones have inherent variations and inclusions. We cannot be held responsible for these natural characteristics, many of which serve to enhance the final aesthetic beauty of the installation. Caution should be exercised however concerning how and where such natural materials are installed, as all natural materials may be affected adversely by environmental influences. For this reason, slates are not recommended in showers, pools, spas, steam showers or exterior vertical installations. Consult your tile retailer for more details and recommended uses.
Natural stone tiles are quarried and fabricated to satisfy industry specifications and are recommended for some identified residential and commercial uses. Below are a few additional insights beyond the already provided common stone industry installation recommendations.
These are not intended to replace the existing industry guidelines but to allow you to better understand the overall contractor activities. Please be sure of your contractor's certification and references and their familiarity with proper stone installation methods and materials. Only experienced and professional tile installers should install our products. Below are recognized and recommended industry authorities for standards details and for providing proper tile and mosaic installation guidelines:
The ' National Tile Contractors Assoc.' - (NTCA) training (workshops, installation videos, training manuals)
The 'Tile Terrazzo and Marble Association' (TTMAC) and 'Tile Council of North America' (TCNA), 'Ceramic Tile Installation Handbook'
The 'Marble Institute of America - (MIA) www.marble-institute.com
Variations in color, shade, texture and even size are inherent in ALL natural stone products, and only serve to enhance the final beauty of the installation. It is controlled within a range of acceptance. With all tiles, contractors should ensure that tiles are mixed randomly from different boxes as they are being installed in order to ensure acceptable variation and a natural looking blend in the final installation.
NYLON MESH-BACK MOUNTED SHEETS
Smaller mosaic sizes are normally mesh-backed on sheets, making installation convenient, while providing acceptable mortar coverage to maximize bond. Use a 1/4 X 1/4 square-notched trowel and do not flatten the combed ridges created while troweling the bonding material. Apply only as much bonding material to be covered with tile within 10 to 15 minutes or while tile surface is still wet and sticky. Do not allow the bonding material to skim over. With firm, even pressure, apply sheets of tile, with the mesh side set into the bonding material. Push the sheets ¼ perpendicular to the combed material. This will allow the combs to cover the back and eliminate the combed ridges. Use a wooden beating block or rubber grouting float to flatten the surface. Align each sheet as it is installed to create uniform grout joints from sheet to sheet. Allow tile to set until firm. Clean any excess setting material from the surface of the tile with a damp cloth or sponge while the setting material is fresh.
Natural stone tiles can be installed over all conventional tile setting substrates such as walls, floors, countertops, backsplashes, etc. The following are acceptable substrates:
- Well cured mortar beds-ANSI A108.1B Standards (cured a minimum of 7 days).
- Cementitious backer units (CBU) to ANSI A118.9 Standards (Note: An ANSI A108A-2.1.8 membrane is required behind all CBU installations in wet areas).
- Concrete slabs (on grade) cured for 21 days minimum.
- Gypsum board (dry areas only) installed to ASTM C1396 or ASTM C1396M-04 Standards
All surfaces to receive tile should be sound, smooth, flat, clean and free of dust, oil, grease, paint, tar, wax, curing agents, primers, sealers, adhesive residue, release agents or any other deleterious substance or debris which may prevent or reduce adhesion to the substrate. Installation materials / Mortars and Grouts are available through tile dealers, home centers, and major setting material companies.
We recommend that a penetrating sealer or enhancer be applied, as per manufacturer guidelines and instructions, to maintain the natural appearance of the stone and to provide immediate protection from accidental water or oil borne staining. Many setting material suppliers have complementing sealers and cleaners within their range of products.
For additional information visit these established stone care professionals websites:
ADHESIVES - MASTICS
Organic Type 1 adhesives (mastic) are considered acceptable for wall applications in dry areas.
However, with larger format natural stone tiles the adhesive (mastic) is sealed off at the edges, which is like putting a lid on the can of adhesive, resulting in the adhesive remaining wet on the backside center portion of tiles and bond is not properly achieved; therefore, adhesives should be a consideration for adhering smaller mosaics only.
Choosing the best mortar for the job is important to assure a long-lasting installation. With larger format natural stone tile units, once the tile has set firmly, the longer you can leave the surface ungrouted the better - we recommend 48 hours.
Types of Setting Materials - There are numerous thin-set mortars available which are suitable for adhering natural stone to floors or walls in dry areas. Please consult the manufacturer's product data sheets for specific installation instructions. We recommend that you choose a premium quality, polymer-modified mortar with outstanding flexibility and bond strength, meeting or exceeding ANSI A118.4 material specifications.
Grout color can dramatically effect the final aesthetic appearance of any natural stone mosaic installation and thus should be selected carefully. Natural stone mosaic tile has varying degrees of surface texture that will collect grout during the grouting process. While thorough cleaning after grouting will remove most of the grout, there may still be remaining grout within the pinholes or surface creases. The amount of grout visible after installation will depend primarily on the color contrast between grout color and tile color, how well the tiles were cleaned during grouting, and viewing distance. The aesthetic appearance of grout left within the tile, not just the grout joints, has a way of aesthetically unifying the overall grout and tile (if coordinating colors are used), but can also aesthetically alter it from initial expectations.
The majority of all natural stone is installed using a cementitious gray color, which is representative of most dimensional and building stones or exterior patio or plaza stone applications. This is also the most forgiving tone and representative of common practice.
Grouting may be done after tile is firmly set, we commonly recommended approximately 24 hours after installation. Immediately before grouting, dampen the surface of the stone. Alternatively, apply a surface sealer following the manufacturer's instructions. Apply sanded grout with a rubber float, making sure that grout joints are completely full and free of voids and pits. Clean the surface after grouting with a clean, damp cloth or tile industry hydrophilic sponge. These sponges are used for all clean-up of ceramic and stone tile, especially after grouting and easily rinse clean while filtering out particles for a clean surface. Allow grout to set until haze forms on the tile and the grout in the joints sets firm. Use a soft, clean, dry cloth to polish off haze and remaining grout residue. This step is key to avoiding unwanted grout residue and should be done as the work progresses, while grout is fresh and before it hardens. The final cleaning of grout haze is done approx. 30 - 45 minutes after initial grout cleanup and tile polishing is done with a clean, dry cotton cheesecloth or terry towel approx. 12 hours after grouting. Allow the grout to cure for a minimum of 7 days before aggressive use or steam cleaning.
Once again, it is imperative to follow the manufacturer's instructions for
the products and, if in doubt, please consult the dealer you purchased the setting materials from or your installer for more information.
We make no representations as to the fitness for purpose of these third party Mortars and Grouts.
- When mixing setting and grouting materials with electrical mixing devices DO NOT exceed 300 RPM (or the manufacturer's recommendations).
- All mortars and grouts need to slake (sit) 10-15 minutes after mixing, and remixed before using.
- Wear appropriate gloves and mask when working with dry and wet installation products.
- All methods and material choices should be reviewed with the setting-material supplier or manufacturer.
- All mortar beds must be cured a minimum of 7 days before natural stone tile is to be installed.
- Areas to be submerged, such as ponds, pools or fountains should be cured no less than 21 days before filling
INSTALLATION TOOLS -
1/16 Grout Spacers
Grout Saws & Blades
Natural stone Cutter
Knee Pads and Gloves
Mixing blades or paddles
Dust Brush and Scoop
Low tack painter's tape
Measuring Tape and Square
Dust Masks and Eye Protection
TROWEL SIZE - Trowel sizes are always intended as a guideline only and results should be checked during installation to make sure that proper coverage is achieved. Check the setting material supplier's recommendations which are commonly provided on the bag or pail.
BACK-BUTTERING MORTAR - The practice of back-buttering is not always recommended with natural stone. Adequate coverage of 80%+ is achievable with proper combing and seating of the tiles. We recommend the application of a straight combed troweled mortar. According to ceramic industry field reports, laboratory bond tests have determined that using the direct bond thin-set method (on cement mortar beds cured 7 days), can achieve equal bond strengths to the back-buttering methods.
COMBING MORTAR - The most satisfactory results have been achieved in straight-combing the mortar to the wall, placing the tiles and then seating them, by pushing the tiles perpendicular to the combed mortar, forward then back, rolling the combed mortar into itself and coating the back of each tile, thus maximizing coverage and bond.
When considering floor placement of larger natural stone tile units, conditions of slip-resistance
requirements should be addressed. If polished/honed natural stone is placed into floors, when exposed to wet area conditions it will act like slippery ice. These decorative elements should be mixed with other tumbles, honed, or natural cleft finishes, providing greater slip-resistance or placed at perimeters, away from primary foot traffic.
EXPANSION JOINTS (Joint Placement)
It is vitally important that proper allowance be made for movement in natural stone installations.
All hard surfaces like ceramic, natural stone and stone installations require expansion Joints!
All buildings will move. Therefore, accommodation for this movement is necessary. To properly review and place expansion joints, the best time to discuss and deal with the issue is before the installation takes place to avoid problems and any finger pointing after the installation is completed.
For additional information, consult the Tile Council of North America's Handbook --Section 'Movement Joint Design Essentials EJ171-[Current Year]'.
Natural stone tile expands and contracts more than ceramic and porcelain tile. This movement needs to be accommodated in the installation, particularly where temperature changes may occur.
Be sure to use caulked joints on all inside corners where walls intersect. This recommendation is a standard installation procedure for ceramic tile and is even more critical with natural stone tile installation. Natural stone tile is a very durable material but only when installed properly. Stone should not be subjected to excessive mechanical or thermal shock. All installation materials should be used according to the manufacturer's instructions.
Generally, the allowance for movement should be made around the perimeter of the room and any hard abutments within the tiled area / cold joints. All installations require these perimeter expansion joints. It is essential that vertical and horizontal planes be caulked, NOT grouted. The minimum width for the perimeter joints is ¼ (6mm). If the perimeter will be covered with a base molding, then the joint can be left open to allow for the movement. If the joint will be exposed, then it should be treated with a suitable flexible sealant or caulking. In addition, if the size of the installation is large enough to warrant field movement joints, they should be placed as directed as outlined by the construction documents or the North American Tile Council's Handbook for Ceramic Tile Installations - Detail EJ171-[Current Year].
EXTERIOR APPLICATIONS - This will require more frequent and wider expansion joint placement and widths. It is NOT advisable to cut in expansion joints after the tile or stone installation has been placed and grouted. Damage can occur before saw cutting and may be irreversible. Therefore, the best course of action is following industry requirements to construct the joints as the work progresses. In addition, the space left for the movement joint should be clear of anything that can potentially restrict movement, including thin-set mortar, spacers, dirt and debris.
CUTTING NATURAL STONE TILES
Mosaic natural stone tiles are best cut with a quality wet saw. To prevent rough edges, natural stone tiles must be cut in a slow manner. Turn the tile upside down and cut half way through, then flip tile over and continue to cut through tile, this will minimize chipping. Sharp cut edges should be sanded smooth with a polishing stone or fine carbide grit sandpaper after cutting.
Drilling holes through natural stone tile can be accomplished with a diamond core bit using a drill set at a low speed (250 to 300rpm). Misting the tile and drill bit with a spray bottle of water during drilling is recommended. If tiles have not been installed, drilling from both sides will minimize chipping and cracking. Additionally, if partitions or fixtures are to be attached with anchoring bolts, drill holes 1/8 larger to avoid stress transfer to the tile.
The installer shall take precautions to protect the finished work from damage by other activities. Do not allow construction traffic on fresh tile or grout joints. Cold Weather - The curing of tile installation mortars, adhesives and grouts is retarded by low temperatures, thus finished work and setting materials should be protected from freezing. Personal safety requires using protective eye wear, dust mask, and gloves, when required. Take a careful and methodical pace and avoid fatigue; reduce any potential hazards while cutting, drilling and installing natural stone tiles.
CLEANING & MAINTENANCE
Normal cleaning of natural stone mosaic tile can be done with room temperature water and light duty diluted neutral detergent cleaner. Natural stone tiles can be routinely cleaned with any non-abrasive cleaning solutions that are commonly recommended for both natural stone and tile - SC Johnson Windex ® or 'Fantastik ® ' (Clean & Shine) f or examples are both natural stone and light-duty hard surface cleaners. The Tile Council of America offers detailed grout cleaning information on their website, under Technical Services URL: www.tileusa.com/faq_main.htm
Four Primary Supplier Recommendations Additional Information
STONE AND PEWTER ACCENTS (SPA), INCLUSIVE OF LUNADA BAY TILE AND MALAGA COVE TILE PRODUCT BRANDS
SPA provides product information and information concerning installation procedures and maintenance practices to assist each of it's customers in making selection, usage, installation and maintenance decisions. Customer's selection and usage of SPA products and the installation procedure and maintenance practice employed by each customer are outside the direction and control of SPA and are strictly and completely the choice and responsibility of each customer and their installer. SPA does not warrant any product for any specific use, nor any installation procedure or maintenance practice, and expressly disclaims all asserted claims after installation of SPA products.