I've got a single tile in the shower that seems a little loose, should I be buying a whole bag of adhesive & mixing it just to put this one tile on or is there something else I can use?
Depends what tile is fixed to. Wall or floor tile? And over what surface like wood or plasterboard ect. Can buy small pot or ready mixed adhesive and grout in one that may do job. Maybe get tile up and look before you head off to DIY or tile shop
Just stick it with some grab adhesive and grout it up. If it’s a smallish white tile, just buy a tub of ‘fix and grout’ and be done with it.
probably, but one of the polymer type are better as they’re a bit more liquid. Stixall, sticks like **** etc.
How long after can I grout it back in after sticking it on with one of those? Only reason I ask is it's a mates house & it's the only shower they have.
A warning. There is a risk this is more than "just one loose tile" if it's on plasterboard. I had this once in a new house and found after removing one, that the plasterboard was mush and everything alongside it was also almost falling off. You may be lucky, but if the PB is wet, be prepared to strip it all off, replace with waterproof tile backer board and refix. - You may find you only have to do the bottom rows. My "go to" grab adhesive is geocell "the works" which will work with wet surfaces. Or it might even turn in to a full bathroom refit....