Washbasin trap McAlpine WHB1-32 low-profile with self-closing silicone membrane 25mm

The McAlpine WHB1-32 low-profile washbasin trap is designed to fit beneath washbasins where space is limited. It features a self-closing silicone membrane with a 25 mm opening that allows water to drain while maintaining an effective seal against sewer gases. The compact shape and low height make it suitable for installation in shallow cupboards or wall-hung basins, and it connects directly to standard 32 mm waste piping for domestic and commercial bathroom use.

Advantages

This trap offers a reliable odour barrier through its self-closing silicone membrane, reducing the risk of unpleasant smells without needing a traditional water seal. The low-profile design saves space under the basin and simplifies installation in tight cavities. Constructed for straightforward connection to standard waste systems, it provides durable performance with minimal maintenance and a hygienic silicone surface that is easy to clean.

Suitable for

• Compact washbasins in small bathrooms or cloakrooms
• Wall-hung basins with shallow installation depth
• Under-sink cavities in fitted furniture where height is restricted
• Commercial washrooms where low maintenance and odour control are required

Key specifications

• Type: low-profile washbasin trap with self-closing membrane
• Membrane material: silicone
• Membrane opening diameter: 25 mm
• Connection size: compatible with 32 mm waste piping
• Height: reduced/low-profile design for shallow installations
• Application: domestic and commercial bathroom washbasins

How to use

Install the trap directly to the basin waste outlet and connect it to the existing 32 mm waste pipe, following standard plumbing practice and ensuring secure joints to prevent leaks. The silicone membrane remains closed when the basin is not in use, opening under water flow to allow drainage and then returning to a sealed position. Periodically inspect the membrane for debris and clean with a mild detergent if necessary to maintain reliable sealing.

Usage recommendations

For reliable performance, ensure the trap is fitted in a horizontal alignment without undue stress on joints and avoid using aggressive chemical cleaners that can degrade silicone. If installed in a commercial setting, schedule periodic checks to remove limescale or deposits and confirm the membrane closes fully between uses.