Channel width is mainly a design decision. Slim channels (around 40–60 mm visible) suit minimal bathrooms; wider channels increase flow capacity and are easier to clean. For most residential showers, a slim channel with adequate depth performs well — width matters more at high flow rates.
What width affects
| Factor | Effect of channel width |
|---|---|
| Flow capacity | Wider channel holds more water over the outlet — helps at high flow |
| Appearance | Slim channels read as a shadow line; wide channels read as a feature |
| Grate rigidity | Wide grates need more support to resist deflection under load |
| Cleaning access | Wider channel is easier to clear along its length |
| Tile cutting | A narrow channel needs a narrower cut in the tile field |
| Body height | Generally independent of width, but check the specific model |
Practical selection
- Residential shower, standard head — slim channel, standard depth
- Rain shower or multiple outlets — check flow rate; if marginal, a wider channel or deeper body helps
- Accessible bathroom — ensure the grate is rated for wheel loads regardless of width
- Tile-insert drains — the insert needs a cut piece of tile, so very narrow channels may be impractical for large-format tile
The flow relationship
Flow rate through a linear drain depends on the water depth over the outlet, the outlet size and the channel geometry — not on visible width alone. A narrow channel with a deep body and large outlet can outperform a wide channel with a shallow body. Compare published flow rates at the same test head rather than judging by width.