What is a sump, open jointed and extension units?? - What is a sump, open jointed and extensi

[WollyDrain]

Hello all

I was hoping I could pick the brains of someone in the know about some drainage questions, I am new to the world of drainage and recently started a new job that requires me to know a little about the subject.

The issues/questions I have is as follows:-

1. I have a document that states that I need to install a catch pit with a sump depth of 250mm below the lowest pipe in the catchpit, what on earth is a sump??
2. In the same document it states “ collector drains should be laid open jointed� I know what a collector drain is but what does it mean when it states laid open jointed???
3. Finally the same document states “ channel drains should be installed without the use of extension units� I know what a channel drain is but what does or is an extension unit?

The above may seem like silly questions but my research on the internet has come up empty handed. Can anyone help at all.

Links to pictures would be very useful.

Thanks

[local patios and driveway]

a catch pit is just what it says on the tin itsthere to catch all the junk and silt etc, the sump is the bottom of the catch pit its basically an area that holds all the junk etc so the catch pit still runs freely while the sump catches anything you downt want in the pipe. look at fish tank sumps for a clue.

the pipe just meansits not a continous roll of perforated pipe, its the pipe you would imagine is under groundmthat can be joined together.

as for the drainage extensions? i confess i dont have a clue

[local patios and driveway]

sorry for what seems terrible spelling my ipad has a cracked screen and it picks random letters sometimes...