Key Differences
| Feature | Slot Drain | Grated Channel |
|---|---|---|
| Appearance | Narrow slot — discreet, linear finish | Visible grate — functional appearance |
| Typical applications | Thresholds, patios, contemporary paving | Driveways, car parks, roads, industrial areas |
| Load class range | A15 (most slot types); some B125+ | A15 to F900 |
| Hydraulic opening | Smaller inlet area | Larger inlet area — higher flow capacity |
| Maintenance | Requires narrow-access cleaning | Grate removes for direct access |
| Grate visible? | No (slot only) or concealed paving | Yes — grate material is a visible feature |
| Forti Nova examples | Pave-A-Drain, Pave Slot, Alu Edge Slot, Threshold channels | All polypropylene, polymer concrete, driveway, C250–F900 ranges |
When to Choose a Slot Drain
Slot drains are the right choice where visual impact is the primary concern — at bi-fold door thresholds, patio edges, block-paved pedestrian areas and contemporary garden hard landscaping. The narrow slot profile sits discreetly in the surface, making drainage almost invisible.
Slot drains are generally A15 rated in their basic form, which means pedestrian-only applications. If vehicle access is possible, confirm the load class of the specific slot-drain product before specifying it.
When to Choose a Grated Channel
Grated channels are the standard choice for driveways, car parks, roads and industrial areas. The grate provides a larger hydraulic opening, better load distribution and easier maintenance access. For B125 and higher applications, grated polymer-concrete channels with ductile iron or composite grates are the typical specification.
Heelguard grate patterns are recommended for any area where pedestrians will also use the channel — the tighter pattern prevents heel and bicycle-wheel entrapment.
Frequently Asked Questions
What is the difference between a slot drain and a grated channel?
A grated channel drain has a visible grate running along the top — typically in polypropylene, galvanised steel, ductile iron or composite. A slot drain has a narrow open slot instead of a grate, giving a more discreet appearance. Both collect surface water along a linear run.
Are slot drains suitable for driveways?
Some slot-drain systems are rated for B125 or higher load classes and are suitable for driveways. The Polypropylene Pave Slot channel is A15 rated and pedestrian-only. Always confirm the load class of the specific slot drain product before installing it in a vehicle area.
Which is easier to clean — a slot drain or grated channel?
Grated channels are generally easier to access for cleaning because the grate lifts out, allowing direct access to the channel body. Slot drains have a narrower opening and may require specialist cleaning equipment for longer runs.
Can slot drains be used at bi-fold door thresholds?
Yes. The Pave-A-Drain and aluminium threshold channel ranges are designed specifically for threshold and bi-fold door applications. These are narrow-profile slot-style channels with aluminium or polypropylene grate options.