Wallbarn Ltd

The SIPHON outlet is a variation on the design of the standard drain connector in EPDM which incorporates the perforated flange and spigot.

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Tough, durable and flexible drain connector, used for downpipes and circular outlets on a roof or terrace within the main body of a concrete deck. It is suitable with SBS and APP bituminous membranes, including built-up felt, mastic asphalt, hot melt and other liquid applied membranes and consists of a spigot which is inserted into a hole to connect to the outlet drainage pipe and a flange which is sandwiched between two layers of waterproofing membrane. The flange is perforated with a series of holes around the profile to allow the membrane underneath to pass through the holes and give a secure bond when the second layer of membrane is installed above it.

The spigot is manufactured in a slight cone shape to give easy installation and to prevent it from rising out of the hole. There are also multiple rings on its exterior, which help to ensure that no water can travel back up. The drain connectors are designed to sit inside an HDPE outlet pipe with a snug fit and a range of size options are available in relation to the relevant outlet pipe size.

This differs from the standard drain connector by including a siphon mechanism to help eliminate bad smells and odours emitting from the drainpipe up to the roof or deck. A small amount of water is held in a well, effectively sealing the drainpipe. As the rainwater runs off the roof and into the outlet, the water level rises over the internal lip and flows into the drain pipe.

General information




Holes throughout the face, waterproof seal


Ethylene propylene diene monomer rubber


220 x 360 x 73 x 64 x 78 x 172 x 76 mm

Specification data

Product Reference

EPDM Drain Connector With Anti-smell Siphon

Outlet pipe width

80 mm

100 mm

110 mm


Not required


To suit drainage outlet

Standard product features


EPDM (Ethylene Propylene Diene Monomer rubber).


220 mm.

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