Layout, Measurement and Setting Out
Layout, measurement and setting out tests whether you can translate a drawing into a balanced, accurate installation. The exam looks for datum lines, squareness, grout-joint allowance, cut size, sightlines and movement-joint planning before the first tile is set.
Core rules
- Establish a datum and square the room using the 3-4-5 method or diagonal measurements; do not trust existing walls.
- Include the grout joint in the layout module: tile length plus joint width.
- Centre the pattern, but adjust to avoid cuts narrower than half a tile at walls or thresholds.
- Plan sightlines at doorways, main viewing walls and changes of material; place full tiles where they read best.
- Mark control lines and a grid for large areas; check tile caliber and pattern direction before spreading adhesive.
- Locate movement joints at perimeters, changes of plane, and at spacing required by the specification.
Worked example
A wall is 3.05 m wide. Tile is 300 mm × 300 mm with a 3 mm joint, so each module is 303 mm. Dividing 3050 ÷ 303 = 10.07 modules. Ten full modules would use 3030 mm, leaving only 20 mm total - about 10 mm cuts at each end, which look poor and are difficult to cut. Instead, use nine full modules: 9 × 303 = 2727 mm. The remainder is 3050 − 2727 = 323 mm, giving cuts of about 161.5 mm at each side. That is more than half a tile and gives a balanced layout. The reasoning: the layout must account for joints and visible cut width, not just the number of tiles.
Traps
Measuring from out-of-square walls; forgetting grout joints in the module; centring without checking cut size; ignoring door thresholds; mixing tile calibers; failing to snap control lines; planning no movement joints.
Key points
- Square the area with 3-4-5 or diagonal checks.
- Add joint width to tile size when calculating modules.
- Avoid cuts narrower than half a tile where visible.
- Set control lines from a datum, not from walls.
- Plan movement joints before installation.