Mosaic is a floor or wall decoration made up of many small, usually square pieces — tesserae — set side by side in a bed of mortar or adhesive. The pieces are of natural stone, fired clay, glass or glazed ceramic, and the joints between them are part of the image.
Mosaic is one of the oldest building finishes there is: it is known from Greek and Roman antiquity and reached a high point in Early Christian and Byzantine architecture, with gilded glass mosaic in domes and apses.
Types
- Floor mosaic — usually natural stone: hard, wear-resistant and with a closed surface
- Wall mosaic — more often glass or ceramic, including colours that would be too fragile underfoot
- Gold mosaic — a leaf of gold sandwiched between two layers of glass, used in churches and formal rooms
- Sheet (mesh-backed) mosaic — the modern form, with the pieces pre-glued to sheets usually 300 × 300 mm, so whole sheets are laid at once
Application
With mesh-backed sheets, mosaic is well within reach of a competent DIYer. Watch these points:
- Substrate. Flat, dry, sound and dust-free. Unevenness shows up immediately with small pieces; level it first
- Adhesive. Use a flexible tile adhesive suited to the format and the substrate. Under glass mosaic, white adhesive is almost always needed because grey adhesive shows through
- Wet areas. A shower needs a tanking system — waterproof membrane and jointing tape — behind the mosaic. The mosaic itself is not waterproof, and neither is the grout
- Grouting. For shower floors and worktops, epoxy grout is dense and easy to clean. Note that the proportion of joint in mosaic is high, so you need more grout per square metre than with ordinary tiles
- Cutting. Straight lines are cut through the mesh; individual pieces are shaped with a mosaic nipper or a wet saw
- Slip resistance. Precisely because of that high proportion of joints, mosaic gives comparatively good grip on a shower floor — one of the reasons it is so widely used there
Related terms
- Mosaic nipper
- Tiling
- Natural stone
- Ornament
- Moorish Revival
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