Block paving questions about preparing the sub base?

Three questions about a quote and a chat I had with an approved Marshalls installer.

Installer uses a large roller and not a wacker to compact the layers. I am worried that the roller will not get into the corners so is this OK?

He also proposes digging below 250mm to bury some of the removed existing tarmac in a new area of an expanded drive, as it is cheaper to remove soil by skip than tarmac due to environmental charges. MOT in two layers will still be added from a depth of 250mm.

He also states that a membrane is not required but I am thinking about the MOT finding the gaps in the tarmac sub-grade layer as the months pass.

Ltnman said:

Installer uses a large roller and not a wacker to compact the layers. I am worried that the roller will not get into the corners so is this OK?

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Do you think your car will be able to get into the corners?
Only kidding, the guys usually hit the edges with a hand rammer.

Ltnman said:

He also proposes digging below 250mm to bury some of the removed existing tarmac in a new area of an expanded drive, as it is cheaper to remove soil by skip than tarmac due to environmental charges. MOT in two layers will still be added from a depth of 250mm.

Click to expand...

I cant see a benefit or a problem either way as long as the 'mac is in small enough or well compacted pieces. building control once insisted we remove 'gaseous' materials from sub base environment, saying it could have a detrimental effect. Ho, hum. Personally I would not faff about with saving the mac.

Ltnman said:

He also states that a membrane is not required but I am thinking about the MOT finding the gaps in the tarmac sub-grade layer as the months pass.

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Membrane is not required unless you are building a highway or that you have extraordinary ground conditions.

Thank you for taking the time for your reply