Rainwater Drainage Basics

[MortarThePoint]

4 minutes ago, Big Jimbo said:

In an ideal world design them out ?

 

Sadly the only ideal world exists on the drawing board. I'm working to eliminate as much as I can.

Edited December 5 by MortarThePoint

[Russell griffiths]

They do leak they are the work of the devil, try not to use them, trying to tighten the ring with wet dirty hands is hard work. 

[saveasteading]

2 hours ago, Big Jimbo said:

design them out ?

with 2 or 3 lesser bends and perhaps a slight tweak to pipe direction, almost any angle is feasible, and the bend ends up being gradual which is good for flow.

The adjustable bend must normally be airtight surely? I'd buy Osma for once because at that price they are surely better researched and made.

Build and test before backfilling to be sure.

[MortarThePoint]

1 hour ago, saveasteading said:

I'd buy Osma for once because at that price they are surely better researched and made

 

You'd hope. Osma in general does seem well made but certainly carries a premium. 

[MortarThePoint]

I'm a little disappointed to end up with Bottle Gullies rather than rest bends due to levels. I suspect Bottle Gullies could be a breeding ground for mosquitoes.

[MortarThePoint]

It's really a struggle to maintain 1:100 with a couple of turns.

 

I've wondered about sending the (remaining) furthest downpipe (at 27m) on that run into a channel drain going along the edge of the house. That runs at the surface and you can get a 110mm end cap. That would buy me about 40mm if the channel was laid with a 1:100 fall or 80mm if laid level. 80mm would allow the remaining 22m to fall at (425 - 110 - 25) : 22000 = 1:76. A channel drain here is a bit random though.