clé is honored to share one of our all time favorite materials that has graced the tile community since at least ">     clé is honored to share one of our all time favorite materials that has graced the tile community since at least ">     clé is honored to share one of our all time favorite materials that has graced the tile community since at least ">
  1. Help Center
  2. FAQ's for glazed terracotta

zellige specification guide



clé is honored to share one of our all time favorite materials that has graced the tile community since at least the 14th century. zellige is a tile that has retained its ancient and archaic tile making process and, therefore, has all the primitive qualities that have become synonymous with the monicker - zellige. essentially, a glazed terracotta tile; hand hewn, olive-pit fired and hand chiseled to-size, zellige are a testament of ancient tile craft. we like to refer to them as the prima materia of the tile world. If your order doesn’t contain tiles with pits, cracks, shade/size variations and chipped edges - it’s NOT zellige. 


general description

zellige is a series of glazed terracotta tile, handmade in morocco. It is a low-fired terracotta that is used throughout morocco for all applications- floor and wall, interior and exterior, and water treatments ( pools and fountains ). available in a variety of sizes, and colors, zellige is a prestigious architectural finish for the finest projects. they may be installed using most industry accepted processes, typical for standard ceramic installation on a variety of substrates. clé provides an installation guide for specific installation requirements.

nominal sizes

  • 4x4 tiles (4”x 4”x 3/8”)
  • 2x2 mounted (2”x 2”x 3/8”)
  • 2x6 bejmat (2”x 5.5” x ¾”)
  • 3.5 hex (3.5” x 4” x 3/8”)

available trim

trim is not a typical part of the zellige tradition. trim, in general, is not a tradition of tiles outside of the U.S. and specifically for tiles that have an ancient history. for jobs requiring a finished edge - we recommend the traditional craft of trimming tiles- 

  1. for turning corners and for mud-set tiles, we recommend mitering your tiles. this provides a beautiful corner finish and in the case of a mud-set requiring a quarter round - this substitutes the quarter round finish with a squared miter finish. 
  2. for finishing edges on a vertical surface, we recommend building up your sheetrock surface to allow the plane of the zellige to be on the same plane as your sheet-rocked wall. for a less preferred ( and non-traditional ) edge-trim you may also elect to use schluter style edge-trim. ( see for trim options )

 standard specifications

zellige tile shall be selected by the architect/designer/owner from clé zellige standard sizes, shapes and glazes; and shall meet the requirements of ANSI 137.1 as special purpose tile; ASTM C1088-12, grade exterior, type tbx, for physical properties; and ASTM 1405-12 class exterior for properties of finish. most units will meet pci specifications, but need to be requested as such if required.

all glazes will contain a random quantity of pits, cracks, crazing and edge-chipping and therefore will not meet the crazing requirements of ASTM 1405-12. 

note: interior/exterior specification. ok for wet applications ( pools & fountains ) but NOT Ok for freeze/thaw areas.*

*if specifying in a freeze/thaw area, please be sure to use a waterproofing agent for the installation (clé recommends Miracle 511 Porous Plus) as well as, any TCNA guidelines for installation in a freeze/thaw area. these details will include- flashing the top of a vertical installation to prevent moisture from dripping behind the installation. also for horizontal installations- insuring that the tiles are not installed below grade.


most zellige is provided in a limited stock availability. when stock becomes sold-out, for purposes of specification and depending on volume production fluctuations and shipping limitations, a lead time of 8 - 10 weeks is sufficient in most cases. check with clé for verification of delivery. 

color variation

zellige glaze colors vary from tile to tile, some more than others. these variations are intentional, resulting from our commitment to the use of ancient glaze production methods and use of raw materials. when specifying zellige, if color consideration is paramount, always work from a sampling of 3 or more tiles, which represent the range of color you can expect on the job. unglazed zellige - referred to as the color “natural”– will require the same sealant methods as our standard unglazed tile sealing.


crazing refers to the hairline cracks which may occur in the glaze surface of zellige after firing and is common in hand crafted tile. to minimize the possibility of staining clé recommends using a penetrating sealer or grout release. If sealer or release is required, please test a small section following the sealer/release manufacturer’s instructions.

size variation

all zellige are hand chiseled to size. this creates obvious size variation which is part of the zellige effect. please anticipate size variation in width and length, based on this chiseling. due to shrinkage from wet to fired clay in the firing process, our tiles are subject to size variation in depth, as well. the thickness is 3/8" ( for all sizes except 2"x5.5". that thickness is 3/4")and can vary, along with other specified dimensions.

pitting, cracking & edge-chipping

again, based on the archaic methods of the mining and firing of the terracotta zellige clay body and the impurities found in the raw materials used for the glazes, your order of zellige will contain tiles that are pitted through the glazes to the clay body, as well as have a percentage of about 20%-30% that will contain cracks, crazing and edge-chipping. should your project not want as many tiles containing these imperfections - order at least 20%-30% more tiles, to allow your contractor to cherry-pick these imperfections from your order.

note - clé does not suggest this recommendation as a preferred form of zellige installation, as it falls outside a standard zellige finish and will not yield your project the traditional zellige surface for which they are known.


installation methods should conform to the tile council of america “handbook for ceramic tile installation” (current edition). DO NOT install from unblended boxes. zellige from several different cartons should be mixed to achieve the best overall blend of color and surface imperfections. other systems are available and the manufacturer’s recommendations should be followed. 


clé recommends Mapei Ultracolor Plus FA, however, if you are using "natural" zellige please use Mapei Flexcolor CQ, which is intended for unglazed tiles

It's recommended that zellige not use a grout joint ( should be butt jointed ). based on size variations, wedge spacers can be used to allow for variation in the butted tiles. 

NOTE: grout is customarily used to fill in the pits, chips and cracked portions of the zellige. once grouted space, all the grout should be sealed after installation.


minimal maintenance is required. mild soaps should be sufficient for most cleaning. test any cleaners before general use.

durability considerations

depending on specific site conditions, zellige are subject to wear over time. this inherent traffic pattern is, again, a highlight of using zellige and should be both anticipated and favored. to minimize sizeable traffic damage, a means for people to clean abrasive materials off their shoes before walking on a glazed zellige floor should be provided.