Do not install during excessively humid conditions. An appreciable loss of heating efficiency will result and the ceiling will not remain stable. Yes, if supported independently by an existing structural member. It is best to remove old tiles first. In many cases, the old ceiling may have deteriorated and an adequate hold cannot be obtained.
Costs vary according to product design and performance features.
Armstrong ceilings are adaptable to standard lighting fixtures. All lamps must be rapid-start. Warm white and cool white are most efficient, but deluxe and natural-colored lamps provide a more pleasant atmosphere. Standard rule for light fixtures is two 4' fluorescent tubes for every 75 square feet of suspended ceiling. Armstrong ceilings are treated with a special back coating to resist moisture.