Minimum installation depth depends on the drain body height, which ranges from about 28 mm for ultra-thin models to 90 mm or more for standard units with a full odour trap. Measure the available floor build-up at the drain position, not at the room entrance.
Indicative depth by drain type
| Drain type | Approximate body height | Typical application |
|---|---|---|
| Ultra-thin linear drain | ~28 mm | Renovations, prefabricated bathrooms, side outlet |
| Low-profile linear drain | ~50 mm | Limited build-up with dry-trap or compact siphon |
| Standard linear drain | ~65–90 mm | New build, full odour trap |
| Point drain, standard | ~70–100 mm | Centre-drain layouts |
Actual figures vary by model and by the odour trap or siphon fitted. Confirm against the specific product drawing.
What adds to the required depth
- Odour trap — a water trap needs depth. Very shallow bodies use dry traps or compact cartridges instead.
- Outlet route — a horizontal outlet needs room for the pipe and its fall below the channel.
- Screed cover — the drain needs enough surrounding screed to be stable.
- Waterproofing and adhesive layers — typically 3–8 mm combined.
How to measure correctly
- Measure from the structural slab to the finished tile surface, at the drain location.
- Subtract the tile thickness and adhesive layer.
- Compare with the drain body height plus any required screed cover.
- If the numbers do not work, change the drain — not the slope.
See also shower drains for thin floors and slope requirements.
Send us your available build-up in millimetres and we will confirm which models fit. Request a Quote