Joists and ceiling tiles: CGC pamphlet recommend 3" clearance above all obstructions such as pipes and ducts (1-1/2" with flexible panels such as fibreglass): How serious is this. I defineletely don't want to do this. I've got a 1/2" Cu pipe line (styro tube insulated) that runs 15'. but theres another 2" above it. If it were up to me I'd set up my grid to put the panels within 1/2' of these and continue. Whats up? If there IS such a big difference between std. panels and flexible, there is only one flex option at my local BORGs (ugly if you ask me), white plastic paper over yellow fibre avail. Are there more than one option for this type if I look around elsewhere? The EXTRA 1-1/2" is, IS, a need I have.
Concrete floor and ceramic tiles: on my orig bare concrete basement pour there are some areas less than perfectly contiguous wrt obtaining an even thickness for thinset. How do I know if I need a leveller (what the heck is that), or if I need to mix up some concrete first to level, or how thick I can fill in these areas with the thinset I will use to stick the tiles down. Is there a problem, or better choice, to walking in with the interntion of buying the 79/99 cent/sf tile wrt the above or other consideration?