Removing an old tarmac driveway

[simoncarter]

My drive is currently very scruffy-looking tarmac - lots of potholes and it looks like somebody has spilled a load of concrete on it at some point.

I want to lay a gravel drive and have heard that putting gravel directly onto tarmac (after filling the potholes obviously) isn't a great idea. So my question is, how much of the old drive should I remove? E.g. is it ok to just dig down a few inches, then lay some scalpings and put the gravel on that? Or should I excavate to the full 200mm suggested in the "Driveway and Path Project"?

[collectors]

Best to start again with the 200mm+ depth of type 1 tampered down with a plate Compactor. Then throw a lean mix of sand & cement over the top. Then cover with gravel. Worth also running half round edging stones up the sides to help the base & gravel from moving.

[elwood]

Hi

lift the tarmac should be around 75mm in depth, do a few trial pits with a shovel to check the depth of the exiting hardcore if you have 150-200mm that will suffice.

top the stone up, wack it leaving about 30mm for shingle.

Bye

[simoncarter]

Thanks both, very helpful. Sounds like, as I suspected, the best thing to do to be sure of a good result is to dig it all out and start again. Hope the weather stays good!