Thinest base for sandstone slabs

[rolysatch]

hi

i've got a few slabs left over from doing my patio so want to lay some slabs outside my front door. i've lifted the old slabs to reveal a good condition concrete base which i will lay onto.

if i'm using sharp sand/cement what's the thinest bed i can lay on as i don't want to bring it up too high. the old slabs have just been laid on 10mm building sand cement.

[lutonlagerlout]

assuming grit sand and cement with a bond bridge and SBR in the wet mix around 10-12 mm
I have used this on preformed concrete steps before
just need the flags to be very flat
LLL

[rolysatch]

assuming grit sand and cement with a bond bridge and SBR in the wet mix around 10-12 mm
I have used this on preformed concrete steps before
just need the flags to be very flat
LLL

that sounds good i've probably got about 25-30mm max to play with as the sandstone is thinner than the current slabs but i have a manhole etc that i need to slab upto. and yes i'll be using a bond bridge, thanks for your help!