We plan to install the foam ceiling tiles and crown molding. Which should be installed first?
It can be done both ways. It is faster to install tiles and crown molding after because you do not have to cut exact size tiles for the perimeter for the ceiling. The disadvantage would be if you had a deep profiled tile and you were trying to caulk it, this would take longer than if you would have done crown molding first and tiles after. So ultimately it is up to you which way you go about it.