Covering embedded in-floor radiant heat

[RogerP]

I have a couple of problems. I have a 2-storey bungalow on slab. Cosmetically, the slab has a few cracks (which do not appear to have damaged the pipes carrying the water) that look ugly.

I need a suggestion of something to fill the cracks - just so it looks better.

Secondly, I want to cover the slab with a "finish". Because the slab is used to heat the lower level of the house, whatever is used can't act as an insulator. Hence, carpet is out as is anything requiring a wood sub-floor.

I'm reluctant to just paint it - water on painted concrete makes a great slide, not quite what I want.

Anyway, I'm looking for suggestions. Anything will be considered - go crazy!

TIA
Roger.

[tooltroll]

Tile. Laminate. Carpet would be fine, it has negligible R value.

[RogerP]

The information I didn't give the first time is that my house is off-grid and that most of my hot water comes from either solar panels or a masonry wood heater. DHW is tempered to 120f and the same supply feeds the in-floor.

My niece near Victoria had neighbours who had radiant infloor below the subfloor. The joists are the laminated I-beam type (can't remember the real name). The problem was that in order to get heat through the layers above they had to run 160f in the PEX, which warped and delaminated the joists.

It also takes a lot more energy to heat the water that much. Tile is a great conductor but laminate and hardwood seem to restrict heat movement (aside from the issue of heat-resistant installation.

The only other solution I've come up with is to shut down some of the zones where I want to put a covering. Since the slab is a monolith, the heat should spread but now I have the issue of extra hours running the pump. (note, my house runs on about 4.5KwHr/day, and even that's hard to come by in the winter.)

Can you put laminate directly on concrete? Or does it need a sub-floor?

Thanks for your advice.

Roger.

[tooltroll]

The newer floating snap-together laminates typically go down over a thin foam pad, no glue or nails needed. Leave about 1/2" gap next to walls and cover with molding.
There are also several different concrete finishing products/methods out there, usually some sort of sealer, and dye/pigments [with or without stencils for stone or other effects] and an epoxy-type nonskid coating on top.

[ChrisVJ]

Just in passing you might note that heat transfer may be fast or slow but you can't 'lose' the heat! The only concern might be that in a slab that is not insulated (and it should be if it has heating in it) you could lose some heat to ground, however even the ground under the slab will eventually build temperature and partly act as a heat resevoir. (heat ravels upwards far easier than downwards.) Personally I wouldn't use real wood but any 'floating' engineered floor should work subject to manufacturer's limitations.