Swap out a baseboard for Hydronic?

[neoshade]

Hi,
This will be my first radiant floor, and it's a product of my desire to do something simple, elegant and inexpensive in this bathroom remodel.

I want to remove the existing baseboard heater (hot water) in the small room (6x10') and instead connect its supply lines to 3/8" radiant heat tubing under the tile floor.
I will be using a ledger system in wherein I will place a "false floor" of 3/4" ply 1" below the joists to hold the tubing and a thermal mass of sand, with insulation underneath the ledger to avoid heat loss to the floor below.
I'm also considering a 1" pour of gypcrete, or other lightweight concrete over a standard sublfoor and tiling directly over this.

Regardless, my question is:
Can I connect radiant heat tubing directly to the existing pipes from the baseboard heater, [for this small room] or does a hydronic radiant heat system necessarily require its own manifold system?
- I'll be using a valve for flow adjustment and proper connectors, of course.

Thank you.

[Christopher]

I suppose all you really need is a way for water to get in and out of the room, and some way to regulate the water temperature and flow so it doesn't over or under heat the room. As long as you have that, I don't see why there would be any problem.
Also, make sure this is a closed-loop system. I'd imagine it is, but you don't want any chance of this water mixing with your potable water.

As a side note, I would definitely go for the gypcrete over the sand; sand is pretty bad at being a radiant mass.

[Watts Radiant]

Another option, for that small of an area, is to use WarmWire (electric radiant cables) embedded in thinset. You could space them at 2" on center, and have a good chance of heating the space. This would also save you some height on the floor, if that is a concern.

-MDR