Tile Setting NC II flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Setting-out datum line

A fixed reference line marked on site from which all levels and dimensions are measured. All tile layout heights and grid lines are transferred from this datum, never from uneven site edges.

Finish schedule

A drawing table listing each tile by code, with manufacturer, size, thickness, finish, grout joint width, adhesive type, and location. It links area markings on the plan to the actual material specified.

Notched trowel size rule

Notch depth should be roughly half the tile thickness. Use 6 mm for tiles up to 300 mm, 8–10 mm for 300–600 mm, and 12 mm or more for tiles over 600 mm.

C2 adhesive class

Improved cementitious adhesive under EN 12004, with higher bond strength than C1. It is specified for large-format tiles, wet areas, and demanding substrates; S1 or S2 suffixes add deformability.

3-4-5 right angle method

Mark 3 units along one wall and 4 units along the perpendicular. If the diagonal between the marks measures 5 units, the corner is square and setting-out grid lines can be trusted.

Substrate flatness tolerance

For thin-bed tiling, the substrate should be flat within about ±3 mm under a 2 m straightedge. Out-of-tolerance areas are leveled with patching compound before tiling begins.

Open time

The period after spreading adhesive during which it still wets the tile and forms a bond, often 20–30 minutes. If a skin has formed, the adhesive must be removed and re-spread.

Back-buttering

Applying a thin layer of adhesive to the back of a tile in addition to the combed bed. It improves coverage and bond for large-format tiles, stone, and wet-area installations.

Adhesive coverage requirement

Aim for at least 80% adhesive contact on dry internal floors and 95–100% in wet areas and external work. Lift a tile to check transfer before continuing.

Slaking

The rest period of 5–10 minutes after initial mixing of cementitious adhesive or grout, allowing chemical wetting-out. The mix is then briefly remixed before use to restore workability.

Lippage

The height difference between the edges of adjacent tiles. It is checked with a straightedge and limited to about 1–2 mm depending on joint width; leveling clips help prevent it.

Running bond offset limit

For large-format tiles, the offset between courses should not exceed one-third of the tile length. Half-offset patterns on bowed tiles cause lippage and are avoided.

Shower floor fall

Shower floors are laid to a slope of about 1–2% toward the drain so water does not pond. The waterproofing membrane must follow the same slope beneath the tiles.

Movement joint

A compressible joint provided at perimeters, substrate changes, and regular intervals, filled with backer rod and flexible sealant. It absorbs thermal and structural movement instead of cracking.

Grout slake and remix

After initial mixing, grout rests 5–10 minutes, then is remixed to a smooth paste. This improves consistency and workability; set grout is discarded, never revived with water.

Silicone at internal corners

Internal corners, perimeters, and junctions with fixtures are sealed with flexible sanitary silicone, not grout. These locations move, and rigid grout would crack there.

Efflorescence

White salt deposits on grout or tile caused by moisture carrying salts to the surface. Remove with a proprietary remover, seal the surface, and correct the water source.

Hollow tile test

Tapping a tile with a wooden or plastic mallet; a dull hollow sound indicates insufficient adhesive coverage. Affected tiles are removed and re-fixed with proper coverage.

5S sequence

Seiri (sort), Seiton (set in order), Seiso (shine), Seiketsu (standardize), Shitsuke (sustain). Each step is audited on site, and the fifth step maintains the first four.

Respirable silica control

Cutting, grinding, and dry mixing release fine silica dust that damages lungs. Use wet cutting or dust extraction, wear respiratory protection, and clean with vacuum or damp methods, never dry sweeping.

30 mA RCD requirement

Portable electrical tools on site must be protected by a 30 mA residual current device. Cords are routed overhead or covered, and damaged tools are removed from service.

Toolbox meeting

A short 5–10 minute pre-shift briefing covering yesterday's hazards, today's task assignments, PPE reminders, and open questions. Attendance is recorded with signatures.

Non-conformance report

A written record of work that deviates from specification, stating location, standard violated, evidence, corrective action, responsible person, and deadline for completion.

Material requisition contents

A written request stating quantity, unit, specification, required date, and delivery location. Verbal requests are converted to written slips the same day to prevent errors.

Wet saw blade dressing

When a diamond blade glazes over and stops cutting, dress it by cutting into a dressing stone or abrasive block. This exposes fresh diamond grit and restores cutting speed.

Diamond hole saw use

For pipe penetrations, cut a hole 5–10 mm larger than the pipe using a diamond hole saw. The clearance allows sealant and movement, preventing cracked tiles around the pipe.

Manual snap cutter limits

A manual snap cutter suits straight cuts on ceramic and porcelain up to about 10 mm thick. Hard porcelain, large-format tiles, and natural stone require a wet saw with a diamond blade.

Pot life

The usable working time after mixing, typically 2–4 hours for cementitious adhesive and 30–60 minutes for epoxy or rapid-set products. Set material is discarded, never re-wetted.

Grout joint width by tile type

Typical widths are 2–3 mm for rectified porcelain, 3–5 mm for ceramic, and 5–10 mm for natural stone and external work. The specification always takes precedence over these defaults.

Waterproofing membrane in wet areas

A continuous waterproof layer applied to floors and walls before tiling, typically 150–300 mm up walls and full height in showers. It must be cured before C2 adhesive is applied.

Grout haze removal

After grout sets, polish the tile surface with a dry cloth to remove haze. Wipe with a damp sponge during application before the grout skins, changing water frequently.

Rectification sequence

Identify the defect and cause, record with photos and location, remove the affected tile without damaging neighbors, clean the substrate, re-fix with correct adhesive, then re-grout and cure.