ANSWER The situation that you have found yourself in is very common to our industry. We have received several technical calls about the influence of lighting on finished tile work. The design community has embraced this type of lighting to give a more dramatic lighting effect. Any type of lighting located on or near tile walls accentuates irregularities by casting shadows on the tile surface. The good news is, our industry has addressed this issue in several places: in the TCNA Handbook, page 34; in the NTCA Reference Manual from page 121 to 127; and in the ANSI standards on page 26. There are allowable amounts of lippage in any tile installation.There are charts in both the ANSI stan- dards and TCNA Handbook based on the type of tile, tile size and LATICRETE® STONETECH® Quartz & Porcelain Tile Sealer is a premium water-based sealer d e s i g n e d to protect quartz, por- celain tile and medium- to-dense sur- faces from oil, water and most stains, all while pre- serving the natural look of the surface. The sealer can also be used as a grout release for porcelain tile. In addition to protecting engi- neered quartz, stone and tile sur- faces, STONETECH Quartz & Porcelain Tile Sealer can also be used as a pre-grout sealer to pre- vent potential staining on porce- lain tile. This product is low odor, non-flammable and meets state and federal VOC requirements, making it safe for installers to work with and environmentally friendly. STONETECH Quartz & Porcelain Tile Sealer is available in a 32 oz. (946 ml) bottle that can cover up to 225 square feet (20.9 square meters). www.laticrete.com. ASK THE EXPERTS –––––––––––––––––––––––––––––––––––––––––––––––––––– FLATNESS AND LIPPAGE atness for Ceramic and Stone Tile stallations The finish flatness requirement for ceramic tile installa- ons is 1 ⁄4" in 10' from the required plane according to NSI A108.02.The finish flatness requirement for stone e installations is 1 ⁄8" in 10' from the required plane cording to MIA. ppage in Natural Stone Tile stallations ppage is a condition where one edge of a tile is higher an an adjacent tile,giving the finished surface an uneven pearance. Lippage in stone tile flooring is accentuated om what would be perceived in a ceramic tile installa- on for several reasons. First, natural stones tend to be stalled with tighter joints, particularly because some ones require narrower joints to allow for the use of nsanded grout. Second, natural stones typically have ght or no chamfer at their edges. Third, many natural ones have a high-gloss, polished finish. dustry standards limit lippage between adjacent units smooth-finished natural stone flooring to 1 ⁄32. " When is is not achieved, there is the option of grinding the one tiles in place to eliminate the lippage. This work ust be done by skilled, experienced technicians, with re taken to avoid a wavy-looking finished floor. In me cases, installing contractors plan to grind the nished floor regardless of the lippage amount, usually r the requirement of the client. Lippage should still be inimized to the extent possible during installation to oid extremely thin stone sections after grinding. ppage in Ceramic Tile Installations ppage is a condition where one edge of a tile is higher an an adjacent tile,giving the finished surface an uneven pearance.Lippage is inherent in all ceramic installation ethods and may also be unavoidable due to the tile lerances, in accordance with ANSI A137.1. B) The allowable warpage of the tile modules. C) The spacing or separation of each tile module,which would influence a gradual or abrupt change in elevation. D) Angle of natural or manufactured light accentuating otherwise acceptable variance in modules. E) Highly reflective surfaces of tile modules accentuating otherwise acceptable variance in modules. The following chart is a guideline for identifying acceptable lippage—in addition to the inherent warpage of tile manufactured in accordance with ANSI A137.1—for typical installations of tile: Tile Type Tile Size (in.) Joint Width (in.) Allowable Lippage (in.) Glazed Wall/Mosaics 1×1 to 6×6 1 ⁄16 to 1 ⁄8 1 ⁄32 Quarry 6×6 to 8×8 1 ⁄4 or greater 1 ⁄16 Pressed Floor and Porcelain Tiles All 1 ⁄16 to less than 1 ⁄4 1 ⁄32 Pressed Floor and Porcelain Tiles All 1 ⁄4 or greater 1 ⁄16 CAUTION —This chart does not apply to tiled floors sloping to drains. Lippage will be 24 TileLetter | May 2018