so, they're a block, are they? Just goes to show what a nightmare paving terminology can be! I must update my library with Armstrongs products.
I'm not familiar with this exact product, so let me check it out before making further comment on the ebst laying method. However, the comments made about geo-membranes doesn't hold water, to coin a phrase.
Geo-grid *can* be used to stabilise sub-grades and sub-bases, but it tends to be used on large projects that will be subjected to exceptional stresses, or over 'made-up' ground. If a proper sub-base material is used rather than the rather unspecific "hardcore", there should be no need for a geogrid beneath a residential driveway.
And just how it is supposed to help drainage, I've absolutely no idea. A concrete or other cementitious bedding medium will be more or less impermeable, so what use is a geo-membrane at the interface of the bedding and the sub-base? I wonder if he means a drrainage composite?
Anyway, I'll take myself off to Armstrongs website to learn more about what passes for cobbles up there in the north-east. :~)