'reversing' falls

[ReadingGuy]

Hi,

I am planning a concrete paver block car wash area of around 50 sq. metres in front of my detached garage block but I am having problems with the design. I have bought “The Book� and explored the website but I am still not sure that what I have planned is going to work OK.

The total width garage is 7.9 metres (3 garages) but I was surprised to find that the block has been built sloping down towards the west by around 33mm giving a gradient of around 1:240. The main problem is that the drive/garden in front of the garages slopes down towards the east. The slope in this case is variable but of the order of 1:60 . I plan to have a linear drain running parallel to the garages some 5.7 metres away from them with a E-W fall of 1:180 towards a gully to the east. If I set the fall from the centre of the garages to the linear drain at 1:60 this would give a fall at the west end of 1:92 and a fall at the east end of 1:43

I cannot have the whole drive sloping down towards the west because a) it would look very odd in respect to the rest of the garden and b) there would be no convenient means of draining it.

On the other side of the linear drain, away from the garage, there would be a further section of drive of around 2 metres in length that would slope down to the linear drain with a slope of 1:180 in the east-west direction (to follow the drain) and probably about 1:40 in a north-south direction. However, without going into details, I may be able to alter this latter figure slightly.

The whole plan seems a bit iffy to me mainly because of the area between the garage and the linear drain where I reverse the fall. Do you think that I will get away with this? Frankly, I am at a loss as to what else I can do.

Finally, will the plastic Clark-Drain CLKS series linear channel be strong enough to take a long wheelbase Land Rover as this is the channel that is stocked by most builders merchants in this area. It seems more substantial than some others I could mention.

Many thanks,

Mike

[Tony McC]

I can't see anything wrong with your plan. 1:43 is just about noticeable as a gradient - no need to worry that it will look odd or excessive.

The CLKS channel is fine - after all, it's basically a smooth-lined mould for the concrete bedding and haunching. It's the grating that's the weak link. Go for the heavier-duty thick plastic grating rather than the tinny galvanised jobby.

[ReadingGuy]

Hi Tony,

Many thanks for your reassuring comments. i will let you know how I get on but it will be a little while as I am working alone.

Cheers,

Mike