I wonder if anyone can help me with this please?
I have a concrete floor on which I was going to lay porcelain floor tile but as it is uneven (I can fit a pencil under some corners of a few tiles - so they rock) I decided to lay SLC first on the side of the floor that was uneven. I mixed it as per the instructions (even measuring the water with a measuring jug to prevent overwatering as I've never used SLC before), unibonded the floor as per instructions and poured the SLC. It's taken longer than they said it would to dry because I have no heating as it's being altered but when it did dry it all appeared okay. Unfortunately today (probably 10 days since pouring) when I was looking at it prior to tiling, it has massive hairline cracks through it and it sounds hollow if you knock it. It appears it hasn't bonded to the floor and I managed to lift a lot of it by getting my fingernails/screwdriver under it and lifting it. Can't imagine this is how it should be so I wondered if anyone could advise the likely causes and remedies? Also am I correct in doing it this way or could I just lay the tiles (using professional dry powder - not ready mix) and use the mixture to take up the uneveness as I've been told by some folks the professionals would do/have done to theirs?
I'm a very proficient DIYer but this has got me stumped as I'm not sure whats going wrong - especially as I've followed the instructions to the letter.
Any help from anyone would be much appreciated as it's got me scratching my head.