When setting stone tiles over concrete, how do I deal with concrete contaminants?
Start with inspection of surfaces over which the assembly will be installed. Concrete slabs need to be clear of all contaminants and suitable for moisture absorption. If an ounce or two of water poured onto the slab beads up instead of being absorbed, it means the concrete needs to be scarified to remove contaminants and open up the concrete slab pore structure. Typical contaminants include: curing compounds; mastic residue; drywall mud; paint overspray and paint. Even a burnished concrete slab surface can inhibit moisture absorption necessary for adhesion to concrete.
When working with stone tiles and slabs, how do I gauge setting material tolerances?
Verify the adequacy of the flatness or slope of the concrete slab; take care of proper pitch of the slab for exterior installations. If the concrete slab is not to acceptable tolerance, then either reject the surface or install materials to bring the surface into acceptable tolerances prior to stone tile installation. Maximum allowable variation in the tile substrate is 1/8-inch in 10 feet from the required plane when measured from the high points in the surface for an assembly with direct bond. Maximum allowable variation in a roof/deck or for a mortar bed installation is 1/4-inch in 10 feet from the required plane. The tolerances for the substrate are the same tolerances for the finished stone tile installation. Many failures have occurred because the thin-set mortar, medium-bed mortar or dry-pack mortar is too thick without wire reinforcement to level or flatten the concrete slab to acceptable tolerance. Overly-thick setting materials can result in shrinkage cracking, progressive loss of bond, and wreak havoc with an otherwise successful stone tile assembly. The substrate must be in acceptable tolerance prior to installation of membranes, radiant-heat assemblies, and sound-rated floor assemblies.
How do I address expansion joints in the stone tile assembly over a concrete slab?
Address correct expansion joints for the stone tile assembly and any existing sawcut control joints in the concrete slab. Know how to correctly work with the sawcut control joints. If in doubt, consult with the membrane and/or adhesive manufacturer prior to using the respective product(s). Refer to pages 271 through 275 in the 2011 TCNA Handbook for Ceramic, Glass, and Stone Tile Installation.
When setting the stone tile assembly over a concrete slab, what do I do in regard to moisture migration?
Moisture migration in and from concrete slabs can contribute to deterioration of stone tile surfaces when they are directly bonded to the concrete slab. The Marble Institute of America (MIA) has recommended using a waterproof membrane to reduce moisture migration from and through concrete slab from affecting the stone tile installation. Consult pages 218 – 219 of the 2011 TCNA Handbook for assembly method F122 and F122A: direct bond of stone tile to a waterproof membrane for on-ground concrete and above-ground concrete respectively. American National Standard Specifications (ANSI) 118.10 material specifications for Load Bearing, Bonded, Waterproof Membranes for Thin-set Ceramic Tile and Dimension Stone Installation includes Acceptance Criteria (AC) 115 which requires that where tile or dimension stone is directly bonded to a waterproof membrane, the waterproof membrane must meet ANSI A118.10 requirements. International Conference of Building Officials (ICBO) and International Code Council (ICC) have both adopted AC 115. Read and follow membrane manufacture installation instructions explicitly. Do not bond stone tile to waterproof membranes that do not meet ANSI A118.10 requirements.
What is the associaton's recommendation as far as a trowel size to use when installing an 18"x18"x 3/8" ceramic tile?
For and 18"x18" tile, you should use a medium-bed thin-set mortar. You will probably need a 5/8" x 3/4" loop notch trowel to get the proper 80% coverage for inteior dry areas. Backbuttering is always a good idea to improve coverage.
If a tile installer damages things in my home, should he fix them? As a result of this tile installer’s sloppy work, my arcadia door (where the tile comes up to) now drags and squeaks. Before installation, no problems for 20 years. He also scraped the metal track of the door so I will have to paint the metal. He told me I could take care of both things myself. Shouldn’t he?
This is a fair question, and addresses whether you have a quality contractor. I was a contractor for many years. I assume that the door now rubs and squeaks because the new tile is higher than the old flooring, so the door now scrapes along its bottom. This is an issue that needed to be discussed and decided before work commenced. Our company would seldom modify doors, but there were times when we would subcontract a carpenter (if the door was wood) to cut the bottom of a door. But this was always discussed during bid time, so the client knew there was an additional expense.
As far as damage to other finishes, we always repaired or fixed things we messed up. But then, we were one of the top companies in our area, not the cheapest, so our reputation on customer satisfaction and ethical dealings was of utmost importance to us.
For stone tile installations of backer boards over wood floors, how do I address the issue of deflection?
For installations of backer boards over wood floors, follow the backer board installation instructions explicitly. All stone tile installations, including those utilizing backer boards, require two structural (i.e. plywood) layers, typically totally 1-1/8" in thickness. Floor systems, including the framing system and subfloor panels, over which the stone tile will be installed, must be in conformance with the IRC (International Residential Code) for residential applications, the IBC (International Building Code) for commercial applications, or applicable building codes. Maximum allowable deflection for stone tile under live load is not to exceed L/720. Refer to substrate requirements in ANSI A108, A118, & A136 Version 2011.1 and the 2011 TCNA Handbook for Ceramic, Glass, and Stone Tile Installation.
What are the right setting materials for the stone tile application?
Use the right setting materials for the stone tile application. If in doubt, check the industry standards or contact your setting-materials manufacturer or your stone-tile distributor. Spot mounting or spot setting will work with anchored masonry veneer, but are not recommended for stone tile installations. All stone tile installations should achieve at least 95% bond adhesion with the setting bed continuous from stone tile to substrate. Epoxy is recommended for installation with moisture-sensitive stone tiles. Rapid-setting mortars are recommended for certain stone tiles. Non-sanded grout is recommended for grout joint widths of 1/8-inch and less. Grout joint widths between stone tiles should be of sufficient width to ensure that the grout being used can be placed to the bottom side of the stone tile. The contractor should know prior to installation if impregnating sealers are part of the installation requirements for the finished stone-tile surface.
What if I have additional stone tile application questions?
Always refer to the industry standards. Industry standards include the 2011 TCNA (Tile Council of North America) Handbook for Ceramic, Glass, and Stone Tile Installation which includes Natural Stone Tile Selection and Installation and Assembly Methods for the Installation of Stone Tile (firstname.lastname@example.org or www.tileusa.com or contact Jim Olson at NTCA to order, email@example.com). In addition, consult the current Version 2011.1 edition of ANSI A108, A118, and A136. Importers, manufacturers distributors, contractors and installers should have the industry documents, available in print and on CD. In addition, MIA publishes the Dimension Stone Design Manual in print and on CD (firstname.lastname@example.org).
What is the difference between ceramic and porcelain tiles?
Ceramic tiles have been around for over 2000 years. They typically have a white or red clay biscuit with some form of glaze on top. Porcelain tile cost more than ordinary ceramic tile because you are getting a superior product. Porcelain tile requires the finest natural ingredients and a rigidly controlled manufacturing process that utilizes the most advanced processes and technology. Porcelain tiles are made from an extremely finely powdered clay tablet that is pressed under enormous pressure and heat - several hundred degrees hotter than ceramics. Porcelain tiles are much harder and more dense than ceramic tiles. This allows porcelain tiles to be made in very large formats that would be impossible to achieve in a ceramic tile. Porcelain tiles will also often have a colored bisque that matches the surface glaze, or have a color and pattern that extends all the way through the tile. This avoids the common problem with ceramics where the glaze gets chipped and exposes the color of the clay biscuit underneath.
What is the difference between wall tile and floor tile?
Wall tiles, because they are not intended to be load bearing are typically thinner, lighter and softer than floor tiles. Wall tile glazes are not designed to handle the abrasive forces from foot traffic. Increasingly, floor tiles are being applied to walls and this is no problem as long as the walls are strong enough to support their weight adn proper ceramic tile installation methods are used. However, it is not usual to recommend using wall tiles in floor applications.
As long as you don't chip at the tile with any heavy or sharp objects, tile should last for the life of the home. Tile was found intact in the ancient ruins of Rome and various other places. After all, it's made of finely ground stone, and hardened in a kiln. Just basic maintenance and avoiding heavy drops should definitely keep your tile lasting and looking great for many years to come.
Will sealing make my tiles or stone maintenance free?
Nothing is maintenance free! Sealing makes your surface easier to clean. contanminants can sit on the surface longer, so you have more time to clean up before any staining occurs. On some unsealed tiles and stone, staining can start immediately. Think of your stone sealing product as a bottle of time. No stone sealing product will make a porous surface stain-proof, but will make it highly stain resistant. Using the correct stone cleaning products also makes a difference.
Tile grout is not waterproof. Even with a grout sealer, most sealers used these days are breatheable, meaning moisture can transmit through it, both in and out, so even sealer won't make grout waterproof.
Both marble and granite are quarried, cut and formed directly into tiles. However, they differ on many levels. For instance, granite is an igneous stone. That is, it is formed from molten lava. Granite, which is composed of crystallized minerals, is extremely hard. So hard that it would dull your knives if you used the surface as a cutting board. Marble, on the other hand, begins its evolution as sediment. It is comprised of mainly silt, animal skeletons, shells, and plant matter. Over millions of years, this sediment solidifies into what we term marble. Because its main component is calcium, it can be affected by acids such as vinegar and citrus beverages.
Marble is a mineral and, as such, is porous. In other words, marble may absorb liquids, which can result in staining. Granite is very dense, and as a general rule, does not stain. On colors, however, moisture may penetrate it left for a long time on the granite, but usually any dark spots will dry out and disappear. It is also recommended that marble and granite applications are sealed after installation.
Can my granite tiles or granite countertop be damaged?
It cannot be damaged through normal living. Neither knives nor hot items, such as pots and pans, will affect it. However, like any solid surface, high impact blows have the potential to harm granite. Because of its crystalline structure, it can chip if subjected to hard objects. In the event of severe abuse, a chip can be filled with a granite dust and an epoxy mixture. Additionally, if left unsealed, granite can absorb stains, which can ultimately cause discoloration. Heat from pots and pans or burning liquids will not affect granite under normal circumstances.
In remodeling a bathroom, once the new tile is set, should the grouting, cleaning of grout, and sealing of grout be completed before any fixtures or other items are installed?
I am hoping this note can help ease your mind. Yes, grouting and cleaning any grout residue from the tile surfaces should be completed before installing fixtures. Where the wall tile meets the floor tile, or where tile meets a tub, should NOT be grouted. This area needs to be filled with a flexible sealant (like silicone caulk) to allow for the slight but certain movement that will be occurring at those changes in plane. Sealers are typically misunderstood by consumers. You understand correctly that tile and grout are not waterproof. But the waterproofing (or moisture barrier) is actually designed into the substrate, or the system used BENEATH the tilework. Even if the system were not tiled, the waterproofing would not allow water to damage your structure. The best sealers are the ones that allow moisture or vapor transmission, or breathability. Sealers are not (and should not) be a waterproofing or moisture barrier. Sealers are NOT required in any tile installation, and at best should be looked at as an add-on product that allows the migration of smaller water molecules, but stops the larger dirt and oil molecules from getting a firm grip onto the surface, allowing greater ease of cleaning. Therefore, sealing is good if using a quality sealer, but not required. To your question about the toilet and vanity being installed before the sealer, I hope the previous explanation lets you understand that since the areas beneath these permanent fixtures are protected, and never will need cleaning, there is not really any need to seal the tile and grout where they reside. – Michael K. Whistler, NTCA Workshop Presenter/ Technical Consultant
In working with small format mosaic tile, I struggle with thin-set mortar oozing between the tiles through the grout joints, which makes cleaing the installation a hassle. What techniques would you recommend for eliminating this problem?
There is a method in ANSI - 108.16 that offers some help with reducing thin-set oozing through the grout joints for smaller than 3"x3" mosaic tiles. This method is primarily for paper-faced glass mosaics but can be used with small mosaic tile without paper facing. The part of the method that may be of interest to you is that it calls for back troweling the notched ridges in the thinset so as to create a flat thin-set bed for applying the mosaic tile. I use this method on most all small mosaic tile since it always has close to 100% coverage of thinset on the back of the tiles and very little thinset in the grout joints. - Gerald Sloan, NTCA Training Director
How would I go about installing a 1" thick - marble quarter circle in the corner of a shower as a seat?
Installing a natural stone shower seat ia a very popular option today and has been for the past several yaers, but it does pose some risk to the installer and the end-user. The type of stone chosen and the preparation of the stone to make it suitable for a shower seat is very important. Some stone types are moisture-sensitive and may distort or be damaged due to direct contact to water in the shower even if a penetrating sealer has been applied to the stone. Some of the softer stones such as marble may need to be reinforced with stainless steel rods and epoxy to make them strong enough to support the weight of the expected load of the people that will use them. See more in Nov. issue of TileLetter magazine.
The National Tile Contractors Association has dedicated its staff, volunteers and resources to the betterment of the ceramic tile and allied industries and is engaged in a wide variety of activities on behalf of our members and our industry. Each year, NTCA conducts over 100 programs and seminars around the country, reaching thousands of industry professionals.