Preparation for laying new turf

[shaw7380]

I have brought in a local firm who advertise as turfing specialists amongst other things, however I am concerned with the preparation for the turf and I would like some advise.

The turf is being laid on part of an existing driveway we lifted the blocks that were on an area about 60m2, the contactor then took about 3inches in depth of building sand out I am guessing about 6 tonnes and put it aside, he then rotovated the surface and removed most of the hardcore. My concern is that he then had 4 tonnes of top soil delivered and put that and the sand back into the area to be turfed, he mixed the sand and the soil, the soil did not seem to go far and I now have an area which is likely about 60% sand. His intention is now to lay the turf straight on to that surface without adding any more soil. Today we have had a lot of rain there has been a puddle on the surface for about 4 hours only clearing slightly when I walked on it I sunk about 3 inches into what appeared to be just wet sand. Any feedback would be welcome.

 

[Thermo]

how deep has he put the topsoil?

what sort of topsoil is it, is it very fine, or the normal stuff you would expect to see in your garden?

a picture or two would be really useful before i comment further.

 

[shaw7380]

I would say it is more fine than I would expect to find in my garden. As far as depth of top soil goes there are areas of the intended lawn that are nothing but sand about 3-4inches deep and none of it pure soil but rather a mixture which is more sand than soil. I will try to include some photos

 

[Trazor]

It is always difficult to comment unless we see the problem.
But if you are after an opinion, then read the preparation a good lawn requires, in this website...

http://www.rolawn.co.uk/turf_homeowners_1_3.html

You are the paying customer, make sure you get what you pay for.....

 

[shaw7380]

Thank you for your comments and the useful link, the point I am making is would you expect good results if you lay turf directly onto nothing more than 4inches of building sand containing little or no soil, I am guessing not any research I have done refers mainly to laying on soil and certainly not a bed of sand so deep

 

[Trazor]

A... SMALL amount of sand mixed in with your soil would be OK, and would help drainage.

But grass will not root into sand, and the amount of soil provided with your turf will not be sufficient for it to stay healthy.
You need a minimum of 4" of soil, 6" would be better, to lay your turf on.

In my opinion, some of the hardcore should have been left, then 6" of soil laid on top, this would have given good drainage,and ideal growing conditions.

You said you sank 3" when you walked on this surface, what do you think will happen when you walk on your new turf, when it is wet...???
Your soil needs to be compacted, prior to laying your turf, otherwise it will sink to varying degrees, giving you an undulating lawn.

 

[Thermo]

when we lay a lawn we put a minimum 100mm of sandy loam down before laying, even if its over existing soil. sandy loam is a rich fine soil that has an amount of sand in it, and it is what turf is grown on.

It sounds like hes trying to lay it on sand with a bit of topsoil. the turf will struggle. Also building sand can contain salts which can be harmful to the turf.