underground drainage

[Stephen]

Hello,

I always thought drains were 110mm but I've just seen that Tool station has a 160mm section too. Is this commonly used?

My gutter down pipe used to discharge into a clay pipe. I have moved the down pipe and want to tidy up the clay pipe. The clay pipe is below ground level. I was hoping to buy a hopper and fit this to the clay pipe to give me a nice tidy drain with grate to stop anything falling down it.

The problem is that the hopper is standard 110mm but the clay pipe is something else all together. The bore of the pipe is 100mm but the end is much wider. Would you call it a spigot? If so, the spigot has an internal diameter of 160mm. How can I fit the 100mm pipe from the hopper into the 160mm pipe of the spigot? I was looking for some sort of rubber "doughnut" to forma watertight seal between the two but I cannot find them. I've googled but not found anything.

OTOH aren't clay pipes usually cemented? Should I insert the 110mm pipe and cement around it?

Thanks, Stephen.

[BigWallop]

These joints are usually made with one of these <

>

and are readily available at any plumbers merchants. If you can describe what you need, they will most likely have the exact one for you.

[RubberBiker]

Larger than 110mm drainage is for multi-floor buildings.

There's a whole bunch of stuff to couple modern 110mm drainage to clay.

Screwfix do a flexi-adapter:

the best product I've found is available in Wickes:

is sized for the rubber part to slip into the narrow portion of the clay, with the 110mm push-fit side flaring out into the wider portion of the clay.

Gives a close, firm, fit (lube it!) with a minimal step between 110mm and clay.

[Stephen]

to a new plastic one but didn't think it was quite what I was looking for this time.

I wasn't quire sure what it was for. It sounds like this is exactly what I need. I was thinking I needed something that would completely cover the clay pipe but you are right; it's only the middle that is important. I'll get one of those. Thanks again.