Slate tile on exterior floor in extreme climate
I am going to install various shapes and sizes of 1 inch minus slate tile on a 12 inch thick exterior concrete slab. The slab is covered under an entry roof, is well cured, level but rough, has no expansion joints (probably because it is so thick) and is located in a relatively extreme climate with maximum temperatures ranging from -20F to +95F. Please advise me the best product to use for adhering and levelling the slate on the concrete and also the best mortar/grout to use for the joints between tiles. How wide should the joints be and also please provide me any tips you have for this type of installation because this will be the first time I have installed slate on exterior concrete.