Resources

Contractor FAQ


Contractor FAQ

Click on each of the questions below for answers to commonly asked questions about installing tile. If you have questions that are not covered below, please contact our Technical Service department at 931-484-2110 for assistance.

Q: What is the TCNA? (Tile Council of North America)

Q: What is the NTCA? (National Tile Contractors Association)

Q: What is ANSI? (American National Standards Institute)

Q: What is ISO (International Organization for Standardization)

Q: What is CTEF? (Ceramic Tile Education Foundation)

Q: What are the different Shade Variations for tile?

Q: How long of a waiting period before tiling over fresh concrete?

Q: How much does the tile weigh?

Q: What is deflection, and the allowable amount?

Q: What are some of the signs that there is excessive deflection present in an existing tile installation?

Q: Approximately how much extra tile should be ordered?

Q: What is typically the proper substrate for a residential tile installation?

Q: Concrete substrates must be free of curing compounds and/or sealers in order to obtain proper adhesion. What is a quick preliminary way to test a slab?

Q: What is Lippage, how much is allowable?

Q: What size grout joint should I recommend?

Q: What is the proper trowel size?

Q: What is Efflorescence, and what works best to remove it?

Q: Why is it recommended that a 1/3 off-set be used in lieu of a brick pattern when installing rectangular tile?

Q: What is the required frequency and width of expansion joints in an interior tile installation?

Q: Cove base, why is it referred to as coordinating, not matching?

Q: What is the TCNA? (Tile Council of North America)
It is an international trade association dedicated to expanding the market for ceramic tile manufactured in North America. This organization also publishes the Handbook for ceramic, glass and stone tile installation methods.

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Q: What is the NTCA? (National Tile Contractors Association)
It is a non-profit trade association serving every segment of the tile and stone industry, and is recognized as the largest and most respected tile contractors association in the world.

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Q: What is ANSI? (American National Standards Institute)
It is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international standards so that American products can be used worldwide.

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Q: What is ISO (International Organization for Standardization)
It is the international standard-setting body, composed of representatives from various national standards organizations.

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Q: What is CTEF? (Ceramic Tile Education Foundation)
They provide education and installer certification for professionals working in the ceramic tile and stone industry.

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Q: What are the different Shade Variations for tile?

  • V-1 Uniform (minimal to no difference)
  • V-2 Slight Variation (distinguishable differences)
  • V-3 Moderate Variation (differences in pattern & color from tile to tile)
  • V-4 Substantial Variation (random, sometimes dramatic differences)

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Q: How long of a waiting period before tiling over fresh concrete?
Typically 28 Days is sufficient, but, Relative Humidity level testing may be necessary.

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Q: How much does the tile weigh?
Tile weighs between 4-5lbs per sqft approximately. Thin-set installation methods typically add slightly over one-pound per sqft. Thick-set (1-1/2” mortar bed) installation methods typically add 12- 15lbs per sqft.

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Q: What is deflection, and the allowable amount?
This is the amount of movement in the substrate. The maximum allowable deflection under live load cannot exceed L/360 for tile or L/480 for stone.

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Q: What are some of the signs that there is excessive deflection present in an existing tile installation?
Cracked grout, Powdered grout, Cracked tile, and Loose tile.

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Q: Approximately how much extra tile should be ordered?
Approximately 7% for waste and cuts, plus any attic stock requirements.

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Q: What is typically the proper substrate for a residential tile installation?
¾” tongue and groove plywood (gap sheets 1/8” for expansion relief) glued and screwed every 8” in the field of the board, every 6” along the edges. Install ½” backer board over the plywood in freshly combed thinset for support; fasten backer board per manufacturers’ requirements.

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Q: Concrete substrates must be free of curing compounds and/or sealers in order to obtain proper adhesion. What is a quick preliminary way to test a slab?
Pouring water onto the slab, if it does not absorb, there may be contaminants present.

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Q: What is Lippage, how much is allowable?
Lippage is the difference in height from one tile to the tile next to it. The allowable amount is determined by adding the allowable warpage for a particular tile (this is provided by the manufacturer), plus 1/16” for tile installed with a grout joint greater than ¼”, or 1/32” for tile installed with grout joints less than ¼”.

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Q: What size grout joint should I recommend?
No smaller than 3/16” for calibrated tile, 1/8” for rectified tile.

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Q: What is the proper trowel size?
Tile up to 8 ”x 8” = ¼” x ¼” notches
Tile up to 12 ”x 12” = ¼” x 3 /8” notches
Tile over 12”x 12” = ¼”x ½” or ½”x ½” notches

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Q: What is Efflorescence, and what works best to remove it?
Efflorescence is a white crystalline deposit that is composed of salts, lime and/or other minerals. It occurs when moisture migrates. In most porcelain tile installations, it shows up in the grout joints, mainly because moisture follows the path of least resistance, and porcelain tile is virtually impervious.
To help remove these deposits; it’s best to select an acidic product that has cleaning agents in it. The cleaning agents will help to breakdown the latex properties (almost all grout has latex in it now), while the acid breaks down the mineral deposits. As always, consult with the grout manufacturer.

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Q: Why is it recommended that a 1/3 off-set be used in lieu of a brick pattern when installing rectangular tile?
Because larger tiles are pressed with inherent tension, this tension can sometimes show up in the form of an arc or crown on the surface of the tile. The highest point, being located in the center of the tile, the lowest at the corners. A brick joint puts the highest point of tile (A) next to the lowest point of tile (B). A 33% (or 1/3)off-set reduces this affect.

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Q: What is the required frequency and width of expansion joints in an interior tile installation?
Expansion joints need to be placed every 20’ to 25’, and should be no less than ¼” for interior paver or quarry tile. If the installation will be exposed to direct sunlight or moisture, they need to be every 8’ to 12’. Additionally, movement joints are required where tile work abuts perimeter walls, cove base, curbs, columns, pipes, etc. Silicone sealants may be used for vertical expansion joints, Urethane is recommended for expansion joints occurring in areas that receive traffic.

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Q: Cove base, why is it referred to as coordinating, not matching?
Typically, cove base is made separately from field tile. The shade sent out on a particular order may not be an exact match, but instead, is selected to match the field tile as closely as possible when held in a vertical position. If you lay a piece of cove tile flat next to the floor field tile, it may appear as though it does not match. Instead, the cove needs to be shown next to the field tile in a vertical position, to demonstrate how it will look when installed perpendicular to the field tile.

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