A floor gully is a drainage fitting set into a floor to collect surface water and discharge it into the drainage system. In bathrooms, the term is used interchangeably with floor drain or shower drain; in technical specifications the word “gully” is more common in European standards.
Where the term is used
“Gully” is standard terminology in European drainage standards and in specification documents. “Floor drain” and “shower drain” are the terms more commonly used in trade and product literature. The function described is the same — a floor-level inlet that collects water and connects to the waste system.
Types of gully
| Type | Description |
|---|---|
| Floor gully with odour seal | Trap retains a water seal against sewer gases |
| Floor gully without odour seal | For discharging to a point where odour is not a risk |
| Linear / channel gully | Long narrow inlet collecting water along a line |
| Balcony / terrace gully | Designed for external exposure and drainage of surface water |
| Roof gully | Collects roof drainage — different application entirely |
Why the distinction matters
When a project specification references a standard for “gullies”, the applicable requirements — flow classification, odour seal depth, marking — are defined against that term. Understanding the terminology helps when responding to a specification or tender.
- Specifications may set minimum odour seal depth
- Flow rates are classified at defined water depths
- Marking and declaration requirements may apply
Practical note
If a specification calls for a floor gully and you are comparing it with what a supplier calls a floor drain or shower drain, check the technical requirements rather than the name. See EN 1253 and drainage standards.