Drywall ceiling in garage ?

[injonil]

Or do as I did! First cc60 and then when I noticed it wasn't good, add more to cc30 afterwards. A HELL of a lot of extra work, I can promise!

 

[Mikael_L]

I also vote for cc30.
If it's 120 discs, then cc40 could work well too, cc30 or 45 for 90 discs.

But I wouldn't dare to take a chance on cc60, all reasons already mentioned.

 

[Immobil]

Cc 30 is the right one, and that way you don't have to redo it.