Threshold Drainage System Coupling Adaptors

Adaptors for connecting Alusthetic threshold drains to underground pipework

These coupling adaptors link the Alusthetic threshold drain outlets to standard underground drainage sizes. They allow you to change direction, step up to larger diameters or join the system into existing pipework. The range covers 50mm and 80mm outlet paths, along with a 160mm to 110mm reducer for sites with mixed or oversized pipework.

Simple connections for flexible drainage layouts

Each adaptor is designed to fit onto either the 50mm end cap outlet or the 80mm bottom connector. From there, they connect directly into standard underground pipework, most commonly 110mm. They are suitable for both surface water and foul water systems when used within the correct application.

These fittings help you build a reliable drainage route from the threshold channel to the pipe system already in place.

Adaptor Options

50mm Elbow

Used with the 50mm end cap outlet. Allows a change of direction before joining into the drainage run. Useful where walls, steps or door frames limit space.

50mm to 110mm Adaptor

Steps the 50mm outlet up to 110mm pipe. This is the most common connection method, as 110mm is the standard domestic underground pipe size.

80mm to 110mm Adaptor

For use with the 80mm bottom connector. Allows a straight vertical drop from the channel into 110mm pipework.

160mm to 110mm Reducer (Polypipe UG621)

Used when an existing 160mm drainage line needs reducing to 110mm before connecting to the 50mm or 80mm Alusthetic outlet path. Handy for older or mixed system layouts.

Features and Benefits

• Fits all Alusthetic 50mm and 80mm outlets
• Compatible with standard 110mm underground drainage
• Allows direction changes using the 50mm elbow
• Supports both surface and foul water systems
• Ideal for tying into existing property drainage
• Durable PVC construction

Practical Uses

• Step 50mm and 80mm Alusthetic outlets up to 110mm pipe.
• Change direction using a 50mm elbow where access is tight.
• Connect threshold drains into existing underground pipework.
• Reduce 160mm pipework where larger systems transition to standard domestic sizes.

FAQs

Do these adaptors connect directly to the channel body

No. They connect to the 50mm end cap outlet or the 80mm bottom connector.

Is the 160mm to 110mm UG621 compatible with Alusthetic

Yes. It fits on the pipework side to reduce 160mm to 110mm before joining to the Alusthetic outlet path.

Are these suitable for both foul and surface water

Yes. They are standard PVC drainage fittings and can be used in either system.

Which adaptor should I use for a bottom outlet

Use the 80mm to 110mm adaptor with the Alusthetic bottom connector.

Can these adaptors be used with clay pipework

Yes. You will need a clay to plastic coupler on the clay side to complete the connection.