Water underfloor heating

[Periproct]

I have quite small rooms so by the time furniture is in there isn't a lot of wall left for radiators. So, my cunning plan is underfloor heating of the water variety. My original plan was to splash out on a solid hardwood floor but as the underfloor heating is so much more expensive than a radiator I am considering reusing the existing floorboards if I can get them up without too much damage. I have one other room where the floorboards have been sanded and varnished and I'm happy with them apart from the fact they dent easily.

Would it be a really daft idea to use wood hardener before varnishing?

The only wood hardener I've used was very gloopy stuff, came in a maximum of

500ml and would cost a fortune to cover a floor. Is there anything that would be more easily spreadable and obtainable in sensible quantities?

[Calvin Sambrook]

UFCH relies on free surface area of the floor to act as a low surface temperature radiator. If you are short of floor space you might find there's not enough left to work well. The most you'll get out of UFCH is about 100 to 200 W/m2. Mind you a small room probably doesn't need much heat so I suppose it balances out in the end.

[The Natural Philosopher]

dangerous to use glued on planks over screed with UFH. But no reason not to lay a suspended floor over what are essentially just hot water pipes. As long as you have massive insulation underneath the pipe runs, (50mm celotex MINIMUM), keep the fluid at no more than 50C. and plenty of pipe, that works. Don't skimp on pipe. 4" spacing.

[The Natural Philosopher]

100W/sq meter is what I have. With rigs and furnitiure over floating wood enginnered, its just adequate for a reaosnly well insulated room. 200W will be OK if its double glazed and cavity walled no sweat. That's about 4" spacing.

With UFH small rooms only need few hundred watts.

[Periproct]

Thanks for the replies. I don't like my rooms too hot and from what I've read, you benefit from getting the heat from the floor where you are nearest rather than a radiator convecting it around the room. Any comments on my wood hardener idea? At least reusing the old floor boards means they'd be nice and dry and wouldn't need acclimatizing to the room. I actually don't think the dents in my existing sanded and varnished floor look too bad. Sort of antiqued.