Block paving over concrete terrace - Help

[cw76]

I have a basement carpark, with access for parking on the roof of the carpark. We want to use block paving in herrignbone pattern for the access ailes and parking bays. But usually any concrete platform I've work with before have all been pedestrian areas only so using flags on pedestals was standard to allow for drainage below the flags and off the concrete terrace.
So my question is what way (or can) block paving be laid in this application?
What I'm afraid off is that the buildup underneath (sand bedding) is going to be too denses to allow any moisture to drain anywhere. and that leading to an array of problems both for the paving and the waterproofing of the basement carpark roof...
I have though of using a Permeable Paving system as the clean course aggregate buil-up would allow for better drainage below the block surface, to the outfall point off the concrete terrace. But budget is tight so hoping there is some way we can use standard block paving, but on what sort of build-up.....any ideas or suggestions???
Thanks
???

[Pablo]

Search for fin drains on the main site and you'll find what you're looking for.

[cw76]

Thanks a mill for that, its exactly what i'm looking for... would still a permeable build-up with clean course aggreagate be a better sub-base than a standard flexible sub-base?

actually would I need to specify a sub-base at all? or just a laying course base????

[seanandruby]

You have obviously consulted with a structural engineer about load bearing capabilities on top of said car park roof ???

[Pablo]

No subbase is required. Your best solution would be to use standard paving over 30mm of standard sand over the fin drain. The area should then be primarily drained by normal run off to gullys or channels which in turn will require a soakaway unless you have special dispensation.