We needed a tiler to lay 46m2 of 800mm tiles to a concrete floor in our new shop. Everyone we tried was not available for a month+, but then through an acquaintance, my partner was told of someone who was available. I had my misgivings as I was wondering why he was available while everyone else seemed very busy, but due to time constraints we went with him. I wasn't any more reassured after meeting the tiler, even though he told us he that had 20 years experience, as I asked him if he was going to use a levelling system and he said he didn't need to. I told him I was worried about lipping and wanted a level floor so asked him to use one and I bought him a Mustang levelling system. He then asked us for £200 up front to buy tile adhesive, so we gave it to him.
He started the job last Thursday. I was there when he started as I wanted to see if he was going to back butter the tiles, something a tiler on here told me he should do. Needless to say, he was about to plonk a tile down without back buttering, so I told him I wanted him to back butter the tiles. He said that he would have to buy some more adhesive, but I persisted in saying that I wanted him to back butter.
Fast forward to today. We went to the shop to see how things were going as we knew half the floor had been done and that he would be starting again today. I'm a bit worried to say the least. Some of the tiles are lipping and the reason he gave was because the floor was not even and a little higher in places. I think it's more to do with the fact that he has only used about 2mm of adhesive, we can see this as the top of the tiles (which are 10mm deep) are only 12mm off the concrete. I would have thought it would be sensible to use a thicker bed of adhesive as this would give you room for manoever (up and down) if a floor was out a little, and using such a small amount to my mind, and should the need arise, gives him nowhere to go. I made a point of looking at the amount of adhesive he had used. When he started he brought in 10 x 20kg bags, he's only used three and has done 23m2. Because it is too late to change course, we have let him continue.
Now to my question, do you think I am worrying unnecessarily and the floor will be fine with 2mm of adhesive, or do you think I am right to be worried, in which case, what can be done?
Edit: I hope professional tilers on here don't think I'm being one of those people who is trying to tell a professional how to do their job, particularly as I'm a female with no experience of laying tiles, in fact my only 'experience' prior to starting this, was tiling videos with levelling systems, where they all seem to use much more adhesive.
