Radiant Heat Remodel Question

[FOS373]

Curious if anyone has used Warmboard or EcoWarm in a new or remodel? Pros / cons?

Completing a remodel in which the main floor has ~ 25 year old stapled up (no reflector) radiant heat boiler system. Not very efficient and making an upgrade. Basement has radiant in in the slab and works great.

From what I’ve researched, Warmboard is ~ 40% more that EcoWarm. Doubt that we will ever see a difference in efficiency to warrant that cost.

 

[CoffeeGoat]

I can't speak for warm board, but when I did a remodel I did staple up with a reflector and insulation and it worked very well. I think just adding a reflector/space and insulation would help. Think hard about your final flooring choice, I did floating bamboo hardwood and it worked, but the expansion and contraction was a challenge and the heat transfer wasn't brilliant.

It was a tremendous amount of work...

 

[Mt Al]

I can't speak for warm board, but when I did a remodel I did staple up with a reflector and insulation and it worked very well. I think just adding a reflector/space and insulation would help.

Did something similar on a conversion from hot water baseboard to radiant. I have a crawl space, no basement, so easy to get to the subfloor between floor joists. I used 1/2" pex for each zone and held the tubes right to the subfloor with heat transfer plates (might be different from reflectors?), then put insulation under. Works great and you can feel where the heat transfer plates are in carpeted rooms, hardwood and carpted floored rooms heat up pretty quickly also. The heat transfer plates were pretty cheap compared to alternatives.

I didn't use warmboard because of the high cost and I wasn't changing the flooring at the time.

 

[CoffeeGoat]

These are what I used, they worked really well: https://www.blueridgecompany.com/radiant/hydronic/316/rht-omega-heat-transfer-plates

 

[bradmacmt]

When I build from scratch, I'd always do sleepers w/ gypcrete rather than warmboard et al. In your scenario, I'd do staple-up with fins and save some money. Staple up with fins is still very effective. It's critical to use aluminum foil and a minimum of R30 batts under the staple up.

 

[44thStateSender]

Do yourself a big favor and make sure you buy QUALITY oxygen barrier PEX, NOT plumbing PEX. Big difference. If it's not oxygen barrier, it'll bite you in the butt in a few years. Brands worth buying (not an exhaustive list): Watts, Uponor, Rehau. Also, get a serious air separator, like a Taco 4900, not an oldschool scoop. Radiant loops are more difficult to get the air out than a baseboard system.

As far as efficiency and performance: Gypcrete>Warmboard>Staple-up. And if you're going to redo the staple-up, don't attempt it without heat transfer plates (I'll bet you know that already though, LOL!) As someone else already mentioned, you could just add transfer plates to your existing system, so long as it's oxygen barrier PEX.

If you wanna talk boiler options/accessories, I could discuss that all day long. Make sure you install a modulating/condensing unit. No sense in installing a system that requires 100F water and a conventional boiler that can only deliver 180F.