A complete reference for installing authentic Moroccan zellige, hand-painted ceramic, terracotta, and mosaic tiles.
Authentic zellige and handcrafted Moroccan tiles are fundamentally different from mass-produced ceramic. They are irregular by nature — varying in thickness, edge profile, and surface planarity. A successful installation requires an experienced installer who understands and embraces these characteristics, not one who tries to fight them.
The most important preparation steps are reading this guide in full before work commences, sharing it with your installation contractor, and ensuring the right materials are on site before any tile is set. Attempting to correct problems mid-installation is far more costly than getting it right from the start.
Important: We strongly recommend working with an installer who has prior experience with handcrafted or natural stone tiles. The installation techniques differ meaningfully from standard ceramic tile work.
The substrate is the single most important factor in a successful tile installation. A poorly prepared surface is the leading cause of tile failures — no adhesive or grouting technique can compensate for an unstable, wet, or uneven substrate.
Choosing the correct adhesive system for your specific application is critical. Using the wrong adhesive — even a high-quality one not rated for the environment — will result in tile failure.
| Dry interior walls | Premium white polymer-modified thin-set mortar. Use white (not grey) for lighter or translucent glazes — grey can bleed through and discolour the tile face. |
| Wet areas (showers, spas) | Polymer-modified thin-set rated for permanent wet exposure, or two-part epoxy mortar. Verify the manufacturer's rating for continuous moisture. |
| Submerged pool surfaces | Epoxy mortar or a pool-grade polymer-modified adhesive specifically rated for full water immersion. Standard thin-set is not suitable. |
| Pool waterline | Polymer-modified thin-set or epoxy mortar rated for wet/dry cycling and pool chemical exposure. |
| Exterior (frost-free) | Polymer-modified exterior thin-set. Not suitable for freeze-thaw climates — our tiles are not frost-resistant. |
| Terracotta floors | Polymer-modified floor-rated thin-set. Back-butter each tile in addition to the substrate for full coverage. |
| Adhesive coverage | Minimum 85% back coverage for wall tiles; 95% for floor and wet-area tiles. Use a notched trowel and back-butter large tiles. |
White thin-set only for pale, cream, or translucent glazes. Grey adhesive can telegraph through and permanently alter the tile's appearance.
Proper layout planning before any tile is set saves time, material, and avoids awkward cuts or unbalanced patterns at edges and terminations.
Grout colour has a profound effect on the overall appearance of a zellige installation. A dark grout will emphasise the grid pattern; a tone-on-tone grout will let the tile surface speak. Test before committing.
Glazed zellige tiles do not require sealing on the face, but unglazed surfaces — terracotta, the clay backing and sides of zellige, and all grout joints in wet or high-use areas — benefit significantly from sealing.
| Glazed zellige face | Sealing not required — the glaze is the surface. Do not apply topical sealers to glazed surfaces as they can alter the appearance. |
| Unglazed sides & backs of zellige | Apply Miracle 511 Porous Plus or equivalent penetrating impregnator before grouting to prevent grout staining the clay body. |
| Terracotta (all surfaces) | Must be sealed thoroughly before use and before grouting. Apply 2–3 coats of penetrating sealer, allowing full absorption between coats. |
| Grout joints (wet areas) | Apply a penetrating grout sealer after the grout has cured (minimum 72 hours). Re-seal annually in heavily used or pool environments. |
| Recommended product | Miracle 511 Porous Plus — penetrating impregnator suitable for clay, ceramic, and natural stone. Available from most tile trade suppliers. |
| Re-sealing frequency | Annually for floors and wet areas, or whenever water no longer beads on the surface. Pool tile grout should be checked each season. |
Work only with an installer experienced in handcrafted or natural stone tile. The techniques differ fundamentally from standard ceramic work.
No adhesive or technique compensates for a poorly prepared surface. Flatness, cleanliness, and waterproofing are non-negotiable.
Open and blend tiles from a minimum of 3–4 boxes throughout the entire installation to distribute natural colour variation evenly.
Match the adhesive to the specific environment. Pool-grade epoxy for submerged surfaces. White thin-set for pale glazes. Never compromise on this.
Grout colour dramatically changes the look of the finished installation. Always test on a sample board before committing to full application.
Movement joints prevent cracking as the substrate and tiles expand and contract. Fill with flexible sealant — never grout — and never omit them.
These additional tips come from years of working with professional installers on luxury residential and hospitality projects worldwide.
Apply adhesive to both the substrate and the back of the tile for tiles larger than 4×4". This ensures full contact coverage and prevents hollow spots.
Lightly mist the back of very dry terracotta tiles before setting to prevent them drawing moisture from the adhesive too rapidly.
Avoid tiling in direct sun or temperatures above 30°C. Heat accelerates adhesive and grout set times, reducing working time and increasing risk of cracking.
Use a straight edge continuously across tile faces as you set. Correct lippage while the adhesive is still workable — not after it has set.
Apply a penetrating sealer to terracotta and unglazed surfaces before grouting to prevent grout staining the porous clay body permanently.
Photograph the finished installation and retain your order details, batch numbers, and adhesive product information for future reference and re-orders.
Our team is happy to advise on adhesives, substrates, and project-specific requirements
Moorish Architectural Design · San Francisco, California · Handmade in Fez, Morocco
