Ceiling tile condition

Suspended ceiling tile - 2'x4' stuff? Hopefully the only thing they're supporting is their own weight, which they should easily be able to do unless they've sagged so much from weight above, water, or become fragile with age. The sag would have to be most extreme for the edges to slip out of the track. Generally, if you don't touch them, they stay where they are.

I have no experience with this, but I just installed some. You can get them with the same pattern in different thicknesses. In the store the 1/2" thick tiles (non-"fire-rated", ~$40/case?) would bow when you picked them up with two hands right out of the box. The exact same 2'x4' tile size and pattern, but "fire-rated", and 5/8" ($60/case) was much better. I don't know if it was just the thickness that made them "fire-rated". I'm not sure of the prices, or if they are available in cheaper non-"fire-rated" in 5/8" thickness too. I'm talking about Armstrong tiles at HD, and the random-textured pattern which can be cut in any direction from looking at it. However I have no idea if the 5/8" fire-rated ones will sag eventually over time.