Input Please
 

I own a older house that has "radiant heat" ceiling heat. The plaster has CRACKED so bad I'm concerned that it will fall at any time.....My question is if anyone is familiar with this type of heat and if it would be a problem to remove the plaster and replace it with a 1/4 to 1/2 inch sheetrock, taking the location of the coils into account

heat rises, so all radiant heat I am familiar with is done only on or in floors. are you sure what you see in the ceiling is not to heat the upstairs floors?

if you are keeping the heat as-is then adding sheetrock over it, will put an extra insulating barrier over it and make it much less efficient then it already is and may make it non functional for all intent and purposes.

if it were me I would disconnect the ceiling heat and add radiant heat to floors along base boards or put in central heat, then treat the ceiling as you would any ceiling.

that said, im told once slats and plaster ceilings start cracking and coming lose its a very involved process to make it crack free and solid again. perhaps its best to put up sheet rock over it but I would try to take that stuff down rather then leave it there under sheetrock.

talk to an experienced plaster guy (if they are a few still around) and see what he recommends