Tarmac Contaminated Soil

[BathDIY]

I am looking to sort my back garden, which is largely Tarmac. We want to sew grass seeds to form a lawn in the area.

The current tarmac covering is approx. 2 inches deep and directly onto the earth. I know that a now demolished garage was also in the area. Digging down I can see all sorts of crap, bits of carpet, loads of bricks and black clay.

I wonder will the tarmac and other detritus has contaminated the soil and if so what I should do to remedy this?

 

[conny]

The tarmac will have contained tar oil, cement, bitumen and various aggregates to help it set.

You will need to dig it all out to be sure you are giving your grass the best medium to grow in. If the tarmac has been laid direct on the soil it shouldn't be too difficult to break up and wheelbarrow away from the site. Once you have it all up I would suggest rotavating the subsoil before adding at least 4"-8" of quality topsoil for the best chance of success.