EN 1253 Floor Drains Explained: A Complete Guide for Specifiers

EN 1253 is the European product standard for drains used in buildings. It has expanded from a single standard to a comprehensive 8-part series covering different types of floor drains and their performance requirements. Understanding which part of EN 1253 applies to your project is essential for correct specification, compliance with building codes, and ensuring the drainage system performs as expected throughout the building's lifecycle.

**The Evolution of EN 1253**

Originally published as a single standard, EN 1253 has been progressively expanded to address the growing diversity of floor drain types and performance requirements in modern building construction. The expansion reflects the industry's recognition that different applications demand different performance characteristics — a bathroom floor waste in a residential apartment has fundamentally different requirements from a mechanical odor trap in a hospital surgical suite.

The current EN 1253 series consists of 8 parts, each addressing a specific type of floor drain or performance characteristic. This modular approach allows specifiers to reference the exact standard that applies to their application, rather than relying on a one-size-fits-all standard that may not adequately address the specific performance requirements.

**EN 1253-1: Trapped Floor Gullies**

EN 1253-1 is the most commonly referenced part of the standard, covering floor drains with a minimum 50mm water seal. This is the standard for typical bathroom and wet area drains found in residential, commercial, and industrial buildings worldwide. The 50mm water seal provides reliable odor prevention by maintaining a standing column of water that acts as a physical barrier between the building interior and the sewer gases in the plumbing system.

Key requirements under EN 1253-1 include: flow rate testing (measured in liters per minute at defined head pressures), load class assessment (from pedestrian to heavy industrial), odor tightness testing (verifying the water seal prevents gas transmission), and corrosion resistance testing. For specifiers, EN 1253-1 compliance ensures the drain meets minimum performance thresholds for water seal depth, flow capacity, and structural integrity.

**EN 1253-6: Low-Profile Drains**

EN 1253-6 covers floor drains with water seal height under 50mm. These low-profile drains are used in renovation projects with limited floor depth, raised floor systems, and applications where the standard 50mm water seal trap cannot be accommodated within the available floor build-up height.

The key consideration with EN 1253-6 drains is that the reduced water seal depth provides less protection against siphonage and evaporation. Stricter conditions of use apply — EN 1253-6 drains should only be used where the reduced water seal depth is acceptable for the specific application. In practice, this means EN 1253-6 drains are suitable for frequently-used drains (where the water seal is regularly refreshed) but may not be appropriate for seldom-used drains where the water seal could evaporate.

**EN 1253-7: Mechanical Odour Traps**

EN 1253-7 covers floor drains with mechanical closure devices — traps that use an automated sealing mechanism rather than a water column to prevent sewer gas entry. Mechanical odor traps are particularly valuable in applications where water seals would dry out (seldom-used drains), in underfloor heating environments where heat accelerates water evaporation, and in healthcare environments where guaranteed odor prevention is critical.

Key requirements under EN 1253-7 include: odor tightness testing (the closed mechanism must maintain an airtight seal under specified pressure differentials), durability testing (minimum 100,000 open/close cycles), flow rate testing (the open mechanism must not significantly restrict water flow), and load-bearing capacity assessment. EN 1253-7 compliant traps are restricted to buildings up to approximately four storeys due to pressure differential limitations in tall building drainage stacks.

**EN 1253-8: Combined Traps**

EN 1253-8 covers drains with both mechanical and water seal — providing dual-layer odor protection. Combined traps offer the reliability of a water seal with the backup protection of a mechanical closure, making them suitable for critical applications where odor prevention is paramount. Like mechanical traps, combined traps are limited to low-rise buildings (up to ~4 storeys).

**Key Testing Requirements Across All Parts**

Regardless of the specific part of EN 1253 that applies, all floor drains covered by the standard must undergo comprehensive testing:

**Flow Rate Testing:** Measures the drain's capacity to handle water flow, expressed in liters per minute (L/min). Testing is performed at defined head pressures to simulate real-world conditions. Higher flow rates are required for commercial and industrial applications where peak discharge volumes are higher.

**Load Class Assessment:** Evaluates the drain's structural capacity to support applied loads, from pedestrian traffic (Class N, 1.5 tonnes) to heavy industrial forklift traffic (Class K, 90 tonnes). The load class must be appropriate for the intended application — a bathroom floor waste requires only Class N, while an industrial floor gully may require Class K.

**Odor Tightness Testing:** Verifies that the drain's sealing mechanism (water seal, mechanical closure, or combined) effectively prevents sewer gas transmission under specified pressure differentials. This is critical for maintaining indoor air quality and preventing unpleasant odors in the building.

**Acoustic Performance:** Assesses the noise level generated by water flowing through the drain. Lower acoustic performance ratings are preferred in residential and healthcare applications where noise disruption is a concern.

**Corrosion Resistance Testing:** Evaluates the drain's resistance to corrosion from water, chemicals, and atmospheric exposure. Stainless steel drains typically undergo salt spray testing (24-48 hours) to verify corrosion resistance.

**Implications for Specifiers**

For architects, engineers, and building professionals specifying floor drains, understanding EN 1253 is critical for several reasons:

First, referencing the correct part of EN 1253 ensures the drain meets the specific performance requirements of your application. Specifying EN 1253-1 for a mechanical odor trap application would be incorrect — you need to reference EN 1253-7.

Second, requesting complete test documentation from the manufacturer is essential for compliance verification. European specifiers expect full test reports (flow rate, load class, acoustic, corrosion) as downloadable PDFs from the manufacturer's website or upon request.

Third, understanding the restrictions and limitations of each part of EN 1253 prevents specification errors. For example, specifying mechanical odor traps (EN 1253-7) for a 20-storey residential tower would be non-compliant — the traps are restricted to buildings up to ~4 storeys.

At Melody Drain, all our floor drains are designed and tested to meet the relevant parts of EN 1253. We provide comprehensive test reports, compliance certificates, and pre-written specification sections to support your project documentation. Contact our technical team for EN 1253 compliance documentation specific to your product selection and application.