Newbie poster here, in search of advice. We had an extension built nearly 3 years ago, and a tiled floor with UFH throught the ground floor. I’m happy that both the builder and tiler knew what they were doing, and the overall quality of work is excellent, however we have a few loose floor tiles and if I describe the way they were laid and the layers of flooring they’re on, I’m hoping you kind folks can give me some guidance as to how best to fix them. The main room (lounge) is approx. 7m x 7m, and half the room is a new extension with a suspended concrete block and beam floor, then the following layers: Ecotherm/Celotex board (100mm I assume) UFH pipes on top of Celotex (fixed to 5mm building mesh) Around 3 inches of screed on top. After about 2 weeks drying, Ditra Mat 25 was fixed to the screed throughout the ground floor. Not sure what adhesive was used, from looking at photos it might have been a mix of Ceresit CT60 acrylic plaster with SBR Bonding Primer. This was left for 6 weeks before tiler arrived. Tiler then laid a thin layer of Instarmac UltraTile Floor Leveller on top of the Ditra Mat, and then tiled onto that using UltraTile Proflex SP adhesive. The tiles are 40x40cm vitrified. The loose tiles are mainly around the edges, there are probably a dozen or so that sound loose (hollow), but out of the 80+ sqM of tiles that we had laid that’s a pretty good number I’d say. Problem is several are in areas of foot traffic near doors, and they are now clicking as we walk on them, so I assume it will only get worse unless we do something. I tried a “Shalex Stickit Tile Repair Kit” from Amazon, which squirts thin glue into tiny holes drilled into the grout, but the whole bottle went down around one tile and didn’t make a difference. I have now bought some tubes of Fix-A-Floor Repair Adhesive (Fix-a-Floor | Home - http://www.fixafloor.co.uk/) but before I try squirting this into the grout gaps, I thought I’d ask for advice. What I don’t know, is which of the above layers are more likely to have come apart. Is the failure more likely to be between: Tile/Tile adhesive Tile adhesive/levelling compound Levelling compound/Ditra mat Ditra mat/adhesive to screed There’s obviously no point in me squirting glue where it’s less likely to be needed, so all suggestions welcome. Or should these tiles be fully lifted and reseated? In which case, any volunteers?