Laying Turf
 

In a part of my "garden" there is an area of nasty grey chips (5mx10m, someone told me it is Type 1 - whatever that is). It is very unsightly, and I want to cover it with turf...
What is the best way to go about this? I did think that I'd be ok, just laying the turf on top of the stones, and leaving the grass roots to "reach" down through the chips, but I read somewhere that I should have some topsoil for the turf to root on to?
Or do I need to remove all the chips (not a good idea, flooding from surrounding fields, and the fact there must be about 20 tonnes of the stuff!)
Im not looking to make a bowling green lawn, just somewhere safe for the little uns to play ;)

Thanks for any advice, tips