Top layer - Options for top layer

[bally74]

I'm about to order a top layer for my drive but I am looking for a cheap alternative and permeable options to tarmac,asphalt or concrete.
I have used 4-6 inch scalpings 40mm(not road planings) over membrane for the sub base and wackered them down after driving on them for a while, this is actually quite a hard wearing surface, and seems quite solid.
My question is this, I can get 20mm scalpings, can I not use this for the top surface?

[Stuarty]

If your subbase is type1 or similar and is now in effect a non permeable surface there really aint much point in looking for a permeable finish imo, as the water will still just puddle :/

[seanandruby]

Depending on where you are in the country scalpings can mean any old quarry waste. It would normally be used as a sub base and not for a top dressing. I wouldn't recommend it myself. But each to his own

[Dave_L]

Quite agree Sean - scalpings are basically crusher waste,containing amounts of clay etc etc

[bally74]

Yes I presume it is quarry waste, it was red in colour to begin with but now turning grey. It is permeable, I am looking for a permeable top coat also. I'm just wondering why it isn't used for top coat, it seems to have binded well together, looks ok and is fairly solid as opposed to gravel.

I'm hoping to order some top coat soon but thought there must be a reason why this stuff isn't used for top coat. At present I'm looking at either self binding gravel, which may take a while to settle and may need redressing or south cerney gravel. but these scalpings look good imo.

[Big Phil]

if your scalpings are indeed quarry waste, then it will no doubt contain an element of soil and clay. the scalping screen hopes to remove the shite before processing the quality aggregate. clay will affect permeability and lead to freeze/thaw issues. any soil may cause stability issues and encourage weed growth better than than a rasta's loft.

[local patios and driveway]

any soil may cause stability issues and encourage weed growth better than than a rasta's loft.

Bravo