I am currently putting a shed base together and have started laying slabs on top of edging stones which have been cemented on top of 40mm compacted subbase.
The issue is that I think that Ive made a booboo with the separation of the slabs as the gap between them isn't equal and would like to pull them up and start again from the corner going back to the house so that I can lay them butting up together and will put pee gravel from the end of the slabs up to the house. Also id like to make them more level as decking will laid so that there is no step from the patio doors onto the deck and the existing unevenness will be clear when a straight piece of decking is up against the slabs.
My question is when I look online I get differing thicknesses for the minimum depth of mortar for under the slabs as Id like to raise the slabs slightly; still remaining below the air vent in the house wall, as this will help to level them properly aswell as there currently sitting on Tarmac Ballast which is too course to level easily and I will use just sand. This would probably be under 1" thickness. Would this be OK straight onto the Ballast concrete below? Was planning on 3:1 ratio sand to cement? Also do you use anything particular to paint on the bottom of the slabs as I used plain water to wet them but that was it and they do come off which isn't ideal but I do have to pull really hard to release them.