Can tile go over this floor or not?
Note: I posted this also on the flooring forum, so if you read it there, this is a duplicate.
I have a new house with a 2 in. concrete slab on the main floor (garage and utility room underneath), with radiant pipes. The floor is defective. The contractor poured the slab, stained it a few days later (water-based stain), and sealed it 11 days later--at a time when the outside temp was around 30 degrees (and the house was not yet heated except by contractor diesel/propane heaters). The three main problems are 1) white blooms everywhere--moisture trapped under the sealer, 2) whole huge areas of stain and sealer peeling up, leaving white chalky calcium carbonate, and 3) serious cracking. On the later, the house is extremely well-built but some of the cracks are almost 1/4 in. wide, and the cracks are numerous in the hall areas, including right next to where deep expansion cuts were made to supposedly minimize cracking.
I have had numerous experts look at the floor and/or photos of it and get extremely diverse opinions. My main concern is does the entire slab need to be removed and repoured, or will grinding up the stain and sealer, then putting down tile (rather than more stained concrete since the concrete surface will then be destroyed), suffice? At least one contractor expressed concern that with the wide cracking on such a new house means the concrete pieces may well rub against the radiant tubes and at some point cause a leak--which would of course be the dead of winter when I'm out of state for a few weeks.
I need to get the floors done right, and since this will be a contractor's insurance issue, need to figure out what must be done soon.
Can tile effectively (and durably) be put over defective concrete that was never allowed to dry and has cracked seriously and has lots of calcium carbonate on the surface now? Or does the whole floor need to come up (meaning removing all the cabinets and a lot more to get at the radiant tubing that will have to be redone)? Remember I need to end up with a top quality floor to go with the rest of the extremely well built top quality home.