"flexible" pipe for forced hot water??

I just bought a 100 year old row house which was retrofitted with forced hot water baseboard heat a few years ago. Most ceilings have dropped ceilings about 6" below the plaster ceilings. Most of the plaster ceilings are in good shape and I wanted to restore them.

The problem is, the contractor that installed the heating system placed the pipes, in 2 locations, right between the drop ceiling and plaster. Therefore I need to relocate them above and inside the plaster ceiling.

Is there some type of flexible copper, plastic, etc. material of piping that I can use for this application? I would like to avoid having to knock out a whole bay in between 2 joists to fit a copper pipe.

Also what is the best way to cut the plaster? I was thinking to invest in a rotozip tool. Any suggestions? thanks!

You could use PEX tubing.

I've read that the PEX tubing can hold water up to 200 degrees F. What temperature do forced hot water boilers pump out water at?

Whatever you set it to...but, pex can handle fairly hot water...the higher the temperature, the lower the pressure it will support. You will also want to use the type with an oxygen barrier, otherwise you'll rust out the insides of anything ferrous in your system. A typical boiler is set to around 180-degrees, but usually never above about 200 - it gets too easy to get localized temperatures high enough to boil or flash to steam, and then that creates all sorts of problems. They are run pressureized to about 1 atmosphere (around 15 pounds), which raises the boiling point.