The single touchiest drop ceiling I ever had the pleasure of messing with was for a Toys R Us build-out.
The Fire Marshall had his hair on fire when the retailer's all plastic and cardboard inventory, all the time, for children/fire bugs came to his attention.
So the lid was changed to fire proof and sprinklers aplenty. Further, even the gaps in the lid needed listed fire-stop.
The fixtures were mandated to be LOWER than the fire lid. Hence they could be ordinary 277v low-bays.
Correcting all of the circuit faults -- whew -- NOT fun.
Because of the Fire Marshal, EMT was preferred over MC at every turn. Getting his okay was solely based upon the level of craft and his opinion.
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Why was he so picky? Just the prior month a Toys R Us burned down on the East Coast in record time. Then the word went out to all of the other Fire Marshalls: these toy stores are 'Coconut Groves' waiting to happen!
