Hello Dave
Lets see if this works, thanks gagakev for help
I work for a ground working company and the most common method that we use to construct a hardstanding is as follows
1. Mark out you hardstanding and decide the finish level when deciding the finish level bear in mind that your hard standing needs a fall of 50-100mm if constructed with a paving or concrete finish, if a gravel finish concrete / plastic grid or a porous paving block is adopted then the hardstanding can be level, the following instructions are for a concrete finish
2. Excavate all topsoil and subsoil for a minimum depth of 300mm, remember to allow for the fall. Compact the ground with a vibrating wacker plate (these can be hired from your local tool hire company, who will instruct you how to use it)
3. Lay 150mm (more if required due to depth of excavation) hardcore 6f2 minimum but DOT type 1 is better compact the hardcore with the wacker plate
4. Construct edge 'formwork' from 150x25mm SW fixed to 50x50x600mm pegs driven into the ground, you may have to 'sprag these as well as wet concrete is heavy
5. Lay cheap thin polythene on the hardcore, this prevents water and grout loss into the hardcore preventing the concrete setting too fast
6. Lay steel reinforcing mesh on 100mm concrete spacers ( concrete or engineering bricks are ok) ensure that the mesh finishes at least 50mm from the formwork
7. Pour concrete into the formwork, ( usually 150mm thick) this can be mixed on site ( mix 4-2-1 gravel sand cement or 6-1 all in ballast, cement) or preferably ready mixed concrete as this has better mix proportion control reccomended mix C30N, 50mm slump, this needs at least two or three men to pour this and try to get the ready mix lorry to pour direct into the formwork
8. Tamp the concrete level with a straight edge ( timber or aluminium these again can be hired from tool hire companies) and finish to your choice, normally trowel smooth and then brush the surface with a soft brush giving a level but not too smooth finish or alternativley a tamp finish this is where after leveling the concrete you tamp the top with your straightedge creating lines in your surface
9. If you are doing this in winter it's better not too concrete in frost and if it rains during or after concrete protect with polythene
Other finishes you can use porous or non porous blocks these are usually laid on 50mmm course sand, precast concrete slabs, I would recommend 50mm thick laid on a solid bed of sand (don't use dot and dab bedding), alternativley gravel finish this usually 50mm thickness of 10 or 20mm gravel. There are also concrete and plastic grass grid systems, these are laid on hardcore and again bedded on sand and filled with gravel or topsoil and planted with grass seed
One other point to consder when deciding the finish level is if the hardstanding is against an existing wall ensure that the finished level is 150mm below the damp proof course.
No doubt that other people have other ideas and I hope they voice them
I hope this helps if you have any furter queries please ask
ALB
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