Laying grass question - how much decent soil is needed before laying?

[juslh]

We have recently removed an old patio and beneath we found a mix of mud, sand and a bit of gravel. It goes down a long way! The thought of having to dig it all out is a bit scary. How much topsoil will we need for grass to establish well, would a few inches on top of the grass/mud/gravel be ok? Thanks for any advice.

[WendyC]

Unless there are large rocks, lumps of concrete etc, I wouldn't start digging it up. Perhaps push your fork in as deep as you can to relieve some compaction and brush in sharp sand for drainage. Then lightly fork over the top few inches and get in some top soil to level off. That's what I would do anyway!

[Martin H]

I agree with Wendy. Turf doesn't need deep soil, the biggest worry is drainage from compaction. If you can get the ground so that water disappears fairly quickly after rain, you'll be fine with just a few inches of topsoil over it, whether you are using turf or seed.

This is assuming you just want an ordinary lawn. If you're going for a putting green you'll need a lot more work!