Hi Nick0412
The mix ratio is 2.5 granno 6mm chippings to dust, 0.5 sharp sand, 1 cemment.Depending where you are in the U.k. we would purchase granno from Tarmac.We grout the day before,to get a little suction,we lay first 50mm semi dry,and levelled by shovel,approx;and then furthur top with...