paving slabs

[stevo73]

hi im new to the site and am looking for some advice regarding my newly laid patio.last month i laid 30 sq metres of riven concrete slabs 35mm thick ,random sizes type.put down 8 inches of hardcore,whackered it down and laid the slabs on a full bed of morter(3 building,1 sharp,1 cement)mixed in a mixer and about 40mm thick.looks good ,but have noticed 3 or 4 slabs are slightley moving ,enough to crack the geo fix pointing,its as if these slabs havent stuck to the mortar bed.gonna take up and re-lay these,can i use anything to make the mortar stick to the back of the slab? thanks for any replys

 

[WabbitPoo]

TBH the only reason they might have become un-stuck is if you walked on them too soon after laying, or they were duty/dirty when you laid them, or you used the 5 blob method. Was the mortar bed nice and even?

 

[ColJack]

wet the slabs first.. and water the base..
I was told that if slabs of bricks ( or indeed the soil in this case ) is too dry / porus then it sucks the water out of the mortar so it dries rather than sets..