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TEC Products > Mortar FAQ

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Mortar FAQ

Q. Should I use a thin set mortar on the floor?

A. Yes, thin-set mortars are very effective and highly recommended for floors. For tile larger than 8" x 8" and/or in excessively wet areas (steam rooms) or exterior work thin set mortars are required. Please refer to Stone and Tile Installation Guide to determine what is the appropriate thin set mortar for your particular tile type, size, substrate and service environment.

Q. Should I use a thin set mortar on the wall?

A. Yes, thin-set mortars are very effective and highly recommended for walls. For tile in excessively wet areas (steam rooms) or exterior work, latex modified thin set mortars are required. However, for interior residential installations (showers, bath, kitchen), a Type I Mastic is also appropriate. Please refer to Stone and Tile Installation Guide to determine what is the appropriate thin set mortar for your particular tile type, size, substrate and service environment.

Q. There are thin set mortars (ANSI 118.1) and latex modified thin set mortars (ANSI 118.4 or 118.11). What is the difference?

A. The addition of latex is the main difference in these two types of products. Latex modified thin sets are required for installations involving difficult to bond to substrates (EGP, Vinyl tile, ceramic tile). They are also required for installing difficult to bond to tile (porcelain) and for all exterior applications. Non-latex modified thin sets (ANSI 118.1) can be used for interior applications on concrete, masonry, cement board, drywall, and mortar beds except when porcelain tile is being installed.

Q. Are all latex modified thinset mortars the same?

A. Latex modified thin set mortars are categorized by the performance criteria they meet. ANSI 118.4 mortar is designed for exterior conditions or for use with hard to bond to substrates (existing vinyl tile, ceramic tile) and/or tile (porcelain tile). ANSI 118.11 mortars are designed for installing tile over exterior grade plywood C-C plugged or better (link to plywood installation guide). If you are planning to install tile over a plywood floor, be certain that the thinset specifically states that it is recommended for that purpose (ANSI 118.11). Some Specialty thinset mortars are accelerated such as Quik Flex® and Rapid Flex™. These mortars are designed to set quickly so that grouting can be accomplished only 3 hours after the tile is installed. Quik Flex® is additionally approved for use with plywood. Other Specialty products, such as TripleFlex™ can be used as a tile setting mortar, a crack isolation membrane or a waterproof membrane, depending on how the product is applied. Please refer to Stone and Tile Installation Guide to determine what is the appropriate thin set mortar for your particular tile type, size, substrate and service environment.

Q. Where do the ANSI numbers come from?

A. American National Standard Institute. ANSI has developed Specifications for materials and the Installation of Ceramic Tile.

Q. What thin set do I use to bond ceramic tile to plywood?

A. Latex modified thin set mortars (ANSI 118.11) including TA-345/346 Sturdi Flex™, TA-390/391 Full Flex™, TA-392/393 Super Flex™, & TA-395/396 Quik Flex®.You may also use any of TEC's non-latex modified thin set mortars by mixing them with TA-862 AcrylBond AMA® or TA-872 XtraFlex™ Latex Additives. The plywood must be exterior grade plywood C-C plugged or better. Q. Can I set ceramic tile on a single layer of plywood?

A. No. The floor construction must be at least two layers of plywood with a total floor thickness of 1 1/8". Floor deflection should not exceed L/360 for ceramic tile and L/240 for the installation of marble.

Q. Can I set ceramic tile over Oriented Strand Board (OSB)?

A. No. The primary approved wood substrate for ceramic tile installations is APA (American Plywood Association) exterior grade plywood, C-C plugged or better. Other non-approved substrates include strip wood floors, particleboard, lauan plywood, hardboard, & treated plywood. CDX plywood requires the use of TA-392/393 Super Flex™ Premium Thin Set Mortar.

Q. How do I install cement board over plywood?

A. Refer to the specific Cement board manufacturers guidelines for installation (this is important being as the different cement board manufacturers have different requirements to maintain their product warranties), then select the appropriate TEC thin-set mortar, according to their requirements, for establishing the support plane for the backerboard.

Q. What type of thin set should be used for a concrete swimming pool?

A. TA-345/346 Sturdi Flex™, TA-390/391 Full Flex™, TA-392/393 Super Flex™, & TA-395/396 Quik Flex® mortars are recommended for exterior pools or if the tile to be installed are porcelain. You may also use any of TEC's non-latex modified thin set mortars by mixing them with TA-862 AcrylBond AMA® or TA-872 XtraFlex™ Latex Additives. If the pool is an indoor pool and the tile is not porcelain, any TEC thinset mortar can be used.

Q. How long should I wait to fill the pool?

A. Twenty-one days after the tile are installed.

Q. Can tile be installed in hot weather conditions?

A. Tile should not be installed on substrates or in weather that exceed 90 degrees. Steps should be taken to lower the temperatures or schedule the installation for early in the morning or later in the evening when temperatures are cooler. Additional options that are commonly used on commercial projects is to tent the area to be tiled to provide shade, and also to dampen the concrete about an hour before tile setting, the evaporation of the water will cool the concrete.

Q. What should be used to set fixtures such as a soap dish or towel rack?

A. Fixtures should be set with a thin set mortar, construction adhesive or 100% silicone. Do not use tile mastic.

Q. Do porcelain tiles require a special adhesive?

A. Porcelain tiles require the use of a (ANSI 118.4 or better) latex-modified thin set mortar. See TEC's latex-modified thin set mortars.

 

Q. What size trowel should I use to set my floor tile?

A. No matter which trowel you select, keep in mind that bonding mortar coverage is the issue. Try to achieve a minimum of 80% coverage for interior and/or dry areas and 95-100% for wet or exterior installations. Check a tile occasionally during installation to verify. Typically, for tiles up to and including 6" x 6" tile, use a 1/4" x 1/4" x 1/4" square notch trowel. For tile larger than 6" x 6" up to and including 12 " x 12" tiles, a 1/4" x 3/8" x 1/4" square notch trowel should be used. For tiles larger than 12" x 12" and for substrate variations up to 1/4" in 10' will require a bigger notch such as a 1/2" square notch trowel or a 3/4" round notch trowel.

Q. Can ceramic tile be installed over my existing laminate floor?

A. No, the laminate floor must be removed and the substrate prepared for ceramic tile.

Q. Can I install tile over my existing VCT or existing sheetgoods?

A. Yes. The existing VCT must be a single layer. If the existing VCT (or sheetgoods) is over plywood, refer to plywood installationguide for the minimum floor thickness. Sheetgoods (only non cushion is acceptable) must be a full glue down and not just glued around the perimeter. All linoleum must be sanded, stripped and cleaned of waxes, dirt and any contaminants that will interfere or prevent a good bond [chemically strip first, then abrade]. After preparation, remove all dust by vacuuming. NOTE: Unless you are positively certain that the product you intend to remove is a non-asbestos containing material, you must presume that it contains asbestos. Regulations may require that the material be tested to determine asbestos content. According to the Resilient Floor Covering Installers Handbook& "Do not sand, dry sweep, dry scrape, drill, saw, beadblast, or mechanically chip existing resilient flooring, backing, lining felt, asphaltic cutback adhesive or other adhesive prior to determining asbestos content".

Q. Can tile be installed over adhesive residue?

A. If the adhesive is soft or tacky it must be completely removed. Black Adhesive (Cut-back) residue is acceptable provided the adhesive is well bonded to an approved substrate. Scrape the adhesive residue until it is no thicker than a sheet of paper and almost transparent. Loose or weak adhesive may prevent a good bond between the tile and substrate, resulting in installation failure. Waterbased cutback adhesive is not acceptable, it must be removed with soap and water. To determine, place soap and water on adhesive, observe if adhesive is softened.

Q. Can I install ceramic tile over a plastic laminate countertop?

A. Yes. Plastic laminate is an approved substrate for interior countertops with TA-390/391 Full Flex™ or TA-392/393 Super Flex™ provided the counter is structurally sound and level. To prepare the countertop surface, first chemically strip any sealers or finishes off of the surface, then lightly abrade, thoroughly rinse and let dry.

Q. What should I use to install ceramic tile in a steam room?

A. A For a steam room application, TCA specification SR614-01 should be followed. The ceramic tile can be set with TA-345, 346 Sturdi Flex™, TA-390/391 Full Flex™, TA-392/393 Super Flex™, or TA-395/396 Quik Flex®. You may also use any of TEC's non-latex modified thin set mortars by mixing them with TA-862 AcrylBond AMA® or TA-872 XtraFlex Latex™ Additives.

Q. How should ceramic tile be installed over Gypcrete?

A. Due to the moisture sensitivity of gypsum based underlayments, ceramic tile cannot be installed directly over Gypcrete without the use of a waterproof membrane. TA-324 Triple Flex™ or TA-329 Crack Isolation Membrane must be used on top of TA 861-primed Gypcrete prior to installing the ceramic tile with one of TEC's latex-modified thin set mortars. A detailed procedure is available via the FaxBack system (document #1250 ).

Q. What latex should be added to AccuColor® Grout?

A. TA-869 Acrylic Grout Additive.

Q. Does latex have to be added to the AccuColor® grout?

A. While the addition of an acrylic additive in place of water is a good idea as it adds strength, flexibility, and water resistance to the grout, latex additive is required only when the grout will be subjected to freeze/thaw conditions. Latex additive is not recommended with grout when installing marble. For other natural stone and some textured tile, a grout release (GroutRite™) may be required to facilitate effective grout clean up.

Q. Can a competitors latex additive be used in TEC products?

A. No. Competitor's latex additives may not be compatible with TEC products. TEC latex additives are specifically designed for TEC products.

Q. Can I mix AcrylBond AMA® or XtraFlex™ in TEC grout?

A. No. AcrylBond AMA or XtraFlex should be used only as an additive for TEC thin set mortars. Use TA-869 Acrylic Grout Additive for TEC grouts.

 

Q. When do I need to add latex to TEC thin set mortars?

A. Latex must be added to any mortar that is not already latex modified, when used on any exterior applications. Interior tile applications over properly installed plywood, TEC waterproof and/or crack isolation membranes must also be accomplished with latex modified thinset mortars that are formulated for those specific conditions.

Q. Can I add additional latex to a latex-modified thin set?

A. No. Never add additional latex to a latex-modified thin set.

Q. When should TA-862 AcrylBond AMA® or TA-872 XtraFlex™ be used?

A. Either latex additive can be used with all TEC non-latex modified mortars. TA-872 XtraFlex with give better overall bond strengths, flexibility, and water resistance. TA-388/389 Rapid Flex™ requires mixing with a special additive, TA-873 RapidFlex Acrylic™ Latex additive.

Q. Can I dilute any of the latex additives before use?

A. TA-872 (only when used in mud beds) and TA-861 and can be diluted. Please refer to the Product Data Sheet for dilution ratio with these specific TEC products. For all other uses of TEC latex additives, use full strength.

Q. Can TA-861 Primer and Patch Additive be used with TEC mortars and grouts?

A. No. TA-861 is to be used as a primer prior to applying Self-Leveling Underlayments. It is also the proper additive when using TA-327 VersaPatch™. TEC has specific additives for mortars and grouts.

Q. What do I do if the latex freezes?

A. Allow the latex additive to gradually return to room temperature before using. The latex for TA- 324 and TA-329 are not freeze/thaw stable and should be discarded if they have been frozen.

TEC Mortar FAQ