Question to teh experts - Subbase

[jasona]

Hi All,

I have a company in at the moment doing me some patern printed concrete for a driveway.

They have dug up and taken away the old tarmac surface we used to have there that left what they said was a pretty good base so they wouldn't have to dig down the 8 inches they said they would. They have now laid the sub base over this which is 'old road' chippings. I have a bricklayer on site currently who tells me this stuff is as cheap as chips and has been known to react with concrete. Can someone put my mind at rest or should my contractor be laying proper sub base material.

Thanks for any help

Jason

[Ted]

http://www.pavingexpert.com/archv101.htm

If they have specified Type 1 they should install Type 1. Type 1 is not much more expensive than road planings.

[Rich H]

Ted is right.

Road planings are not suitable as a sub-base. I'd be reluctant to use them under gravel, let alone a rigid surface.

[lutonlagerlout]

dont let them anywhere near with concrete
road planings are a big no no,and TBH if they considered using road planings i would be tempted to pay them for what they have down then bin that contractor
anyone worth their salt uses type 1 ,end of
LLL