Laying turf next to driveway – concrete haunching preventing 100mm soil depth

[Lchanvey]

I’m preparing this area for turf but the concrete along the edge of the driveway is preventing me from excavating enough to achieve the recommended 100mm depth of topsoil.


I’m not sure whether this is part of the driveway’s foundation/haunching or just excess concrete. Should I leave it alone and accept a shallower soil depth, chip some of it away, or is there another way of preparing this area for turf?

 

[Wayners]

Disc cutter along and remove. Leave 50mm .
That's what I think and what I would do.
Can't see it going anywhere

 

[yardcalchub]

I'd agree with cutting the haunching back, and here are the topsoil maths to go with it. Turf wants roughly 100mm of good topsoil, so measure the bed in metres and use volume = length × width × 0.10. As a worked example, a bed of 3m × 2m needs 3 × 2 × 0.10 = 0.60m³. Screened topsoil weighs around 1.1–1.2 tonnes per cubic metre, so 0.60m³ is about 700kg, meaning a single 850kg bulk bag (roughly 0.75m³) covers it with a little left over for raking to level. If you can only achieve 50mm depth, simply halve the figure to 0.30m³. One tip: after cutting the concrete back, rake the exposed sub-base and blind it with a thin layer of sharp sand before spreading the topsoil, which helps stop the turf drying out over the concrete edge.

 

[JohnD]

Your haunching has been done quite badly.

It is more usual to have it at a 45 degree angle, starting about half way up the curb.

Yours looks as it it was just thrown on the ground.