Can someone tell me when you install a permeable driveway can you use any 20mm gravel or shingle as sub base or do you have to use a specific washed aggregate? Is it the same for the 6mm laying course, why not pea shingle instead of 6mm washed aggregate? What would you expect to pay per ton?
ca_surveyor
Favorite Answer
What ever you use it needs to be
1) Self compacting
2) Smooth sided (like pea gravel) so that there is always space between the individual pieces
3) Non degrading (like decomposed Granite which crushes into fine material)
4) Washed - minimal fine dust (which fills up the spaces and seals the driveway
THat is pretty much it.. you can also use a fabric material just under the blocks (if you use blocks) to stop or retard the inevitable silting action.
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rmbrruffian
Smooth sided gravel like pea gravel will NOT compact. The smooth rounded sides keep it from compacting. Coarse crushed material like DG (Decomposed Granite) compacts into a very firm surface.