Drainage gradient

[emidgley]

First of all, sorry if this is a very simple / stupid question. But here goes anyway. I am laying a new block driveway, and wish to incorporate a linear drain on the garage door threshold. The driveway is completely flat left to right, so how do I incorporate a gradient into the linear drain, such that the surface grating is always level with the driveway. Do I simply lay the drain flat, and just rely on the rising water level in the drain to provide a gradient? Any advice gratefully received, be gentle !!

[GaryN]

I think you should be fine laying the Linear channel level, bearing in mind the short overall length it will be.
Regards
Gary

[emidgley]

Thanks for the reply, the overall length of the drain should be no more than 5 meters (it is a double garage door) I guess this is still OK ? I'm assuming this by looking at the suggestion that the fall should be at least a 1:100 gradient. Taking into account that the drain is 100 mm (10 cm) deep, then over 5 meters (500 cm) this would equate to a gradient of 1:50 before the drain overflowed. Does this seem sensible?

[danensis]

The problem with not having a gradient is that sludge doesn't get flushed away. It just means more work swilling it out occasionally - but you can do that when you're washing the car!

[emidgley]

Thanks for the posts, my mind is now at rest!