Hi - We have had our raised patio laid twice by the same builders. The first was laid in -10 c which was a big mistake and the cement didn't go off. I was able to lift the slabs easily with my fingers. I brought this to their attention and they apologised and removed the mortar bed and re-mixed and re-set it all again in warmer weather. The slabs have been down for over two weeks. They have been away whilst we wait for the most recent bout of frost to subside. I went out today and noticed one of the smaller slabs move beneath my feet, I went around and gave other slabs of various sizes a little tug and again as before they lift!! Some seem fully bonded and don't budge but about half of them just pop up with ease and the mortar just feels and looks like wet sand! I'm so gutted and we have paid them nearly all of the money already. I hate that I have to bring this to their attention for a second time and we can't blame the cold this time. What could be happening? Should slabs be able to move and lift? Why are some stuck and others just lift easily? I'm wondering if they are mixing wrong or they have some spoiled cement. Any help would be much appreciated. This is very stressful and I don't want to upset them or have them leave without fixing it. Should I ask for money back and hire somebody else? Thank you.
