Newly seeded lawn growing very patchy, need help!

[simonbilly]

My new lawn has grown very patchy. It was laid late last year, the seeds weren't put down until early November but lucky for me it was quite mild and the lawn did establish before the frost of winter set in. However the grass has grown very patchy and is not thick enough for traffic, very "thin on the ground".

You can see from the pictures the old lawn after I chopped down all the bushes and tree's and even bamboo, all roots dug out, the old lawn dug up and the soil levelled out. About an inch and half of top soil was laid down by a friend although I think it was too clumpy with a lot of large lumps, I did try to break up some of it but think it has effected how the lawn has grown as well.

I have tried putting more seeds down but no new grass seems to grow, the soil is now very stoney as you can see from the pic's of how the lawn looks now but I Don't understand how as so much top soil was laid down? it was a bit stoney underneath but how is it like this now? The soil does seem quite compact now too, it hasn't had hardly any traffic on it as I use the stepping stones, you can still push your thumb in it when it's moist.

I keep the lawn moist with sprinkler but still no new grass?

I'm desperate to get this Lawn sorted for the summer so that my children can enjoy the garden. I'm not an expert gardener so anyone who can give me some advice on how to fix this lawn it would be very much appreciated.