The Brew Cabin

In the construction of my patio which is 2.4 metres wide it is recommended to have a fall of 1 in 40 away from the house which works out at 60 mm.This does seem quite steep. I obviously want to place a table etc on it without it wobbling could I get away with a fall of 30mm? My main question is where do I start the slope, is it implemented in the ground on excavation, in the sub base (crusher layer) or is it adequate to apply the slope to just the compacted sand layer and screeded area?
thanks for your help

You are best advised to create the fall within your sub base level and then make it more accurate with the screed layer.
You will probably get away with around 50mm fall, but dont go any less. It may sound a lot, but when it is laid it is hardly noticiable.
What would you rather have - Standing water or a perfectly level table ?

Nigel

Re-phrase the last bit !!

NO standing water or a level table !!

Thanks Nigel for your reply.Ok 50mm fall it is.I can't find a link to how I go about creating a fall.As you may have guessed I am a DIYer and patio virgin so this was how I was going to proceed.Dig down to about 180 then in order to level the ground lay subbase to a level of around 20mm filling in all the gaps.Then lay a furthur 30 mm of sub base but having a fall from the house of 50 mm if that makes sense.So I would start with around an 80 mm depth of sub base at the house tapering down to 30 at the garden edge.I thought of using 2.4 m lengths of wood which are 30 mm high. At the house side I would place a 50 mm piece of wood under this piece so the angle of the wood now reflects the fall I want then I would fill in between the pieces and skim off the top giving me the fall?
I have got an idea that there must be an easier way and I am making it more complicated than needs be.
Any help would be appreciated.

This is how to do it

Find your finished level height on your house wall - 150mm below dpc level, mark it with a pencil. Use a straight edge ( a piece of timber around 75-100mm by 25-50mm), 2.4m long and level it off your mark on the wall to the end of your patio. Get a wooden peg and hit it into the ground so the top of the peg is 50mm below the bottom of the straight edge when level. These 2 points - the mark on your wall and the peg height are your finished height levels.
Dig out your ground to approx 200mm below your finished heights, thus creating a fall in your ground. Then fill in with an even layer of sub-base 100mm. Keep measuring down from your straight edge. Compact your sub base.
Lavel out your scredding layer evenly and then lay your blocks as per the recommended way - look in the main pages for Tonys do's and don'ts.

If you do it this way, all your levels are even.

Good luck

If anyone else can explain better than me, have a go.!!


Nigel

Top man Nigel, that is so much easier than the way I was going to mess about with.You have been a great help I will let you know how I go on.Bad news today though Jewson's have told me I have to wait 3-4 weeks for the clay pavers ,so I have a dug out area covered in plastic for the next 3 weeks. At least I can tweek my levels and get it right I suppose. If I can lay the sub base and sand it will only be a matter of laying the bricks when they finally arrive.I will be obviously protecting the area I am working on, would it be best to lay the sub base and sand now, and just wait or just lay the sub base then do the sand when the bricks arrive..Read elsewhere on the forum, both don't get your sand wet and don't worry if you do as it should drain off in an hour or two.
Once again thanks for your time and help

johnboi

Get your sub base in now !! and compact it.
Do not put any plastic under the sub base. If you are gonna use anything make sure its a Geo textile type membrane.
The sub base will be ok for weeks/ months after it has been compacted.

Do not put in the sand layer until you are ready to lay the blocks. Make sure you use a grit type of sand - NOT building sand or the like.

Nigel