Installation Tips: GLASS TILE -Category A
We provide these glass 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.
Glass tiles are manufactured to satisfy industry specifications for glazed wall tile and are recommended for residential and commercial use. Glass tiles are impervious to water and stains, highly resistant to chemical attack, and are resistant to fading and discoloration. Below are a few additional insights beyond the already provided common industry installation recommendations. These are not intended to replace the existing industry guidelines, but to allow you to better understand overall contractor activities.
Please be sure of your contractor's certification and references, and their familiarity with proper methods and materials. Only experienced and professional tile installers should install our products.
The following are recognized and recommended industry authorities for standards details and proper installation guidelines:
The 'National Tile Contractors Assoc.' - (NTCA) training (workshops, installation videos, training manuals)
The 'Tile Terrazzo and Marble Association' (TTMAC) and the 'Tile Council of North America' (TCNA), 'Ceramic Tile Installation Handbooks'
As with all hard surface materials, glass tiles and mosaics should not be exposed to high abrasion, heavy traffic or impact.
The end user, not the contractor, is responsible for ensuring that the tile delivered is the tile selected for the project. Open and inspect each carton. Please be sure to make note of any SHADE/LOT number on the boxes and retain for future reference. As the manufacturer, we take every precaution to eliminate defective or unacceptable tiles before they reach the consumer, and we will replace any such tiles at no cost to you.
Upon confirmation that the product is as ordered, the contractor should inspect for suitability, sizing, dye lot shading and tone, by selecting random control samples. Control samples are invaluable, especially in the event that additional material is needed, as they can aid in determining acceptable matching. Once installed, it is no longer the tile supplier's responsibility, and no adjustments will be made. INSTALLATION CONSTITUTES ACCEPTANCE.
SHADING/RANDOM MIXING DURING INSTALLATION
Variations in color, shade and size are inherent in all fired glass products, and particularly so for hand- made products such Lunada Bay/Malaga Cove glass. Such variety serves to enhance the final beauty of the installation and is controlled within a range of acceptance. However, as with all tiles, contractors should ensure that sheets are mixed randomly from different boxes as they are being installed, allowing a final shading from sheet to sheet that will blend together in the overall installation.
PAPER FACE MOUNTING
Please note that many of our glass tiles are mounted 'PAPER FACED' (the paper holding the material is on the front of the glass) with water-soluble glue for ease of installation and for overall appearance. Paper Facing is used on our glass products for two primary reasons: First, to maximize bond by allowing the fullest coverage of bonding materials to the rear of the glass, uninterrupted by mesh. Second, as many of our glass products are transparent or translucent, use of a mesh backing will not work as the mesh would be seen through the Glass. NOTE: While it should be obvious, we have learned of several instances where the installer mounted the paper against the wall, thus installing the tile backwards. Please be certain you make clear to your installer that the glass is to be mounted with the paper facing OUT, to be removed after the mosaic has been seated into the thin-set. The paper should be removed after the glass has mostly, but not fully set, in order to allow final adjusting of material if needed. This is done by wetting the paper with warm water, lightly sponging to soften the glue. Allow a few minutes for the water to soak in, then peel off. Avoid using too much water. You know it is ready when the paper turns a darker brown. Gently peel back the paper against itself from every corner until it has completely released. Clean all excess setting materials and those that may have remained on the tile surface, as well as any haze that may have remained behind, with a damp sponge.
Mesh-backed glass such as our 'Rainbow line' are NOT paper-faced. The piece of brown paper attached to the mesh is there only to prevent the transfer of adhesive from the mesh to the face of the next sheet of glass while in the box. This paper MUST be removed prior to installation.
Always use enough setting material to ensure 100% tile surface coverage but avoid so much that it will squish above the top of the grout joint. Use a 3/16 X 5/32 V-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.
Apply sheets of tile with firm, even pressure, with the mesh side set into the bonding material. Push the sheets ¼ perpendicular to the combed setting 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 excess setting material from the surface of the tile with a damp cloth or sponge while the setting material is fresh.
Glass tiles can be installed over all conventional tile setting substrates such as walls, floors, countertops, backsplashes, etc. Glass tiles are impervious and will not absorb liquid. This makes them stain resistant, frost resistant and durable, and permits use in and under water. The following substrates are acceptable:
• 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.
ADHESIVES - MASTICS (Not Recommended)
Organic adhesives (mastic) are considered unacceptable, due to yellowing, lower bond strengths, and the fact that they set or dry by air exposure. With larger format vitrified or glass tiles the adhesive (mastic) is sealed off at the edges, which is like putting a lid on the can of adhesive. On the backside center portion of tiles, the adhesive remains wet and bond is not properly achieved. Some Epoxies may also be unacceptable due to low flexibility, chemical staining, and degradation under UV sunlight exposure.
MORTAR CHOICES (Recommended)
Choosing the best mortar for the job is important to assure a long-lasting installation. With larger format glass tile units, once the tile has set firmly, the longer you can leave the surface un-grouted the better - we recommend 48 hours. Many of our glass lines are made up of transparent or semi-transparent glass with color contained within the glass. As such, the color of the thin-set will affect the appearance of the glass color, and trowel lines can show through the glass. We recommend the use of bright white thin-set, which will allow the true color of the glass to come through.
Types of Setting Materials to Use
The following (white) Thin-Set Mortars are recommended examples (ALWAYS consult the manufacturer's product data sheets for specific installation instructions):
LATICRETE - (www.laticrete.com )
- 254 Platinum Multipurpose Thin-Set Mortar (no admixture necessary)
- LATICRETE 317 Floor N' Wall Thin-set Mortar mixed with 333 Super Flexible additive
FLEXTILE - (www.flextile.net )
- 52 Versatile Floor Mortar
TEC - HB FULLER - (www.tecspecialty.com )
- Super-Flex Premium Performance Universal Latex-Modified Thin-set Mortar (no admixture necessary)
- Full Set Plus Premium thin set mortar with XtraFlex mortar additive
BOSTIK - HYDROMENT (www.bostik.com )
- ReFlex Ultra-Premium Latex-Modified Thin-Set Mortar (no admixture necessary)
THIS LIST SHOULD NOT BE CONSIDERED EXCLUSIVE OR COMPLETE. There may be other manufacturers who produce suitable installation products, including new products we are not aware of.
Grout color can determine the aesthetic final appearance of any glass installation and should be selected carefully. Be aware that handmade glass tiles have 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, surface creases & crevices. The amount of grout visible after installation will depend primarily on the contrast between the grout color and tile color, how well the tiles were cleaned during/after grouting, and viewing distance. The appearance of grout left within/on the tile (not just the grout joints) has a way of aesthetically unifying the overall grout and tile. Therefore, we recommend choosing a grout color that coordinates with and captures the colors found in the glass itself.
Grouting may be done after tile is firmly set (we commonly recommend a minimum of 24 hours after installation). Apply grout (sanded or un-sanded) with a rubber float, making sure that grout joints are completely full and free of voids and pits. Clean the surface with a clean, damp cloth or tile industry hydrophilic sponge. These sponges are used for all clean-up of ceramic tile, especially after grouting, and easily rinse clean while filtering out particles for a clean surface. Allow grout to set until a 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.
Epoxy Grouts are popular for use with glass tile because of their longevity, strength, and relationship with the glass. Grouts like SpectraLOCK® or Kerapoxy® have a chemical composition that resists stains and breakdown. Epoxy grouts will not fade or change color over time, are non-porous and non-absorbent. When mixed with antimicrobial products such as Microban®, epoxy grouts also inhibit the growth of mold or mildew, a common occurrence with regular cementitious grout. Non-absorbent epoxy grouts require little maintenance, so while they may cost more than cement grout up front, they more than make up for it over time. While the rubbery plastic-like characteristics of epoxy grouts make for a more challenging application, a stronger finished product is obtained. Working with the Epoxy grout is more labor intensive and sticky, and requires more washing after. Set times for epoxy grouts are comparable to their cement counterparts however they do not cure in the same way as cement based products; instead, they thermal set. Once this occurs, there is no way to remove residues or films.
Once again, it is imperative to follow the manufacturer's instructions for the products. If in doubt, please consult your installer or the dealer from which you purchased the setting materials. We make no representations as to the fitness for purpose of 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 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 glass 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.
- Setting material suppliers do NOT represent or warrant that water will not penetrate grouts and mortars. Some water penetration must be expected. If water does penetrate, there will not be damage with proper construction and cementitious materials, and normally the water will eventually wick out. For the most part, such circumstances are minimized and even invisible, behind opaque materials; HOWEVER, this is not the case with translucent glass tiles, which should NOT be used where water is sufficiently present to create visible water behind tiles, such as shower floors.
TROWEL SIZE- Trowel size is always intended as a guideline only and results should be checked during installation to make sure that proper coverage is achieved. With transparent or translucent glass, trowel lines can and will be seen through the glass, and for this reason, small tooth trowels should be used and the glass shimmied into place to create a smooth backing of thin-set (see below).
BACK-BUTTERING MORTAR - The practice of back-buttering is always recommended to help achieve maximum coverage. When setting glass tile 100% mortar coverage is the goal. The only sure way to achieve this is to back-butter the glass. We recommend the application of a straight combed troweled mortar, followed with a skim coat on the back of each tile. According to ceramic industry field reports, laboratory bond tests have determined that back-buttering can achieve equal bond strengths as the direct bond thin-set method on cement mortar beds, cured 7 days.
COMBING MORTAR - The most satisfactory results have been achieved in straight-combing the mortar to the wall, placing the tiles against the mortar and then seating them, by pushing the tiles perpendicular to the combed mortar, forward then back ¼ , rolling the combed mortar into itself and coating the back of each tile, thus eliminating trowel lines. When first set in place, every effort should be made to smooth the thin-set both vertically and horizontally to minimize trowel lines.
When considering floor placement of larger glass tile units, slip-resistance requirements should be addressed. If glossy glass is placed into floors, when exposed to wet area conditions it will act like slippery ice. These decorative elements should be mixed with other units providing greater slip-resistance or placed at perimeters, away from primary foot traffic.
EXPANSION JOINTS! EXPANSION JOINTS! EXPANSION JOINTS! (Joint Placement)
All hard surfaces like ceramic, glass and stone installations require expansion joints. It is vitally important that proper allowance be made for movement in glass installations. 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. This will help 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]'.
Glass 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, especially in showers, backsplashes and cook top areas. This recommendation is a standard installation procedure for ceramic tile and is even more critical with glass tile installation. Glass tile is a very durable material but only when installed properly and 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/outlined by the construction documents or the North American Tile Council's Handbook for Ceramic Tile Installations - Detail EJ171-[Current Year].
EXTERIOR APPLICATIONS - These 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, following industry requirements to construct the joints as the work progresses is the best course of action.
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.
SWIMMING POOLS - Normally, all competent systems rely on the contractor to make choices and recommendations that best suit the conditions, scheduling, availability and other needs of the installation project. In the case of a swimming pool installation, movement joints for a pool should be specified by the architect, not the tile contractor. Expansion Joints in pool applications are absolutely critical to avoid subsequent post-installation cracking / breaking / spalling (flaking) of the glass.
The contractors experience and understanding of
the industry guidelines for pool installations is essential, but there are numerous elements to a customized pool and each needs to be viewed and considered first-hand during designing glass tile installations in water immersed applications. With continuous water immersion applications, minimum cure time after grouting is 21 days before flood testing or filling with water. Follow the setting materials manufacturer's recommended cure times.
CUTTING GLASS TILES
Mosaic glass tiles are best cut with specialty glass mosaic tile cutters, and larger sizes (such as 2 x2 ) are best cut with a wet saw. Use a high quality wet saw with a diamond cut-off or carbide blade. To prevent rough edges, glass tiles must be cut in an extremely slow manner. Turn the tile upside down and cut half way through, then flip the tile over and continue to cut to minimize chipping. Sharp cut edges should be sanded smooth with a polishing stone or fine carbide grit sandpaper.
Drilling holes through glass tile can be accomplished with a diamond core bit using a drill with low speed (250 to 300rpm). Misting the tile and drill bit with a spray bottle of water during drilling is imperative to prevent cracking. On horizontal surfaces, a circular dam made from putty can be shaped to hold water as a reservoir around the drill bit and hole being cut. 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 and finished work and setting materials should all 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 to reduce any potential hazards while cutting, drilling and installing glass tiles.
CLEANING & MAINTENANCE
Normal cleaning of glass mosaic tile can be done with room temperature water and light duty diluted neutral detergent cleaner. Glass tiles can be routinely cleaned with any non-abrasive cleaning solutions that are commonly recommended for both glass and tile - SC Johnson Windex® or 'Fantastik®' (Clean & Shine) for examples are both glass 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
Additionally, on our website, we have supplemented these recommendations with installation specifications provided by some leading North American setting material producers.