The Brew Cabin

Posted: **Mon Feb 06, 2006 12:48 pm**

Hi, wondering if I could get a little advice;

I have a large multi-storey car park which requires drainage at top level. The slab is only 150mm deep and therefor I think too shallow for linear drainage.

The cross fall is 1:60, meeting to create a drainage channel, but there is no longitudinal fall. How do I go about calculating the spacing needed for intermediate gullies?

Many thanks.

Posted: **Wed Feb 08, 2006 12:32 am**

How will you get gullies into a 150mm deep slab?

Do yu know there are shallow linear channels known as Deck Drains that have been developed for exactly this type of problem?

Your discharge capacity is critical - you need to know that, along with the collection capacity of any gullies or linear channels, befire you can work out how many are needed and where they ought to be positioned.

Posted: **Wed Mar 15, 2006 4:51 pm**

Probably a bit late but a useful document would be the 'Design Manual for Roads and Bridges part 3 HA 102/00 Spacing of Road Gullies'

Alternatively, as a rule of thumb we use 150-200 sqm as a maximum area draining to a single gully.

Hope this helps

rjgardner

Posted: **Thu Mar 16, 2006 10:12 pm**

But we still don't know how they are going to get a gully into a 150mm thick slab - linear channel is the only solution that's viable!

The Brew Cabin

Spacing of intermediate gullies - For a large concrete car park