Hi, folks. I'm planning construction of a new house and I'm 90% certain I will do whole-house staple-up radiant heat. I'm looking for suggestions, tips, tricks, etc., specific to the installation of the tubing. I've got a bunch of reasons for wanting to install underneath the sub-floor. I'm also not too worried about boilers and controls right now. Can anyone comment on aluminum plates, best types of fasteners, pex v. pex-al-pex, insulation, etc. I have staple-up radiant in my current home. It works great. I installed it almost 20 years ago. I imagine that the technology has advanced since then.

I don't think the technology has changed since the last time you did it. It is still likely the most expensive and certainly the most performance inefficient way to accomplish hydronic radiant. The only thing more dismal performance-wise would be to finish the floor with carpet or hardwood. Other than that, it will work great, especially if you never experienced anything better.

In my current house I have staple-up with a hardwood floor that is glued down. As best as I can tell it works great. My energy bills are low and my house is warm. What am I missing?

Sailaway is a firm believer in gypcrete as your radiating floor element, and it is an excellent way to do it. But CC floors are not for everyone. If I was building new, I would put it above subfloor(which I am currently doing...

If I may ask, what are your reasons for not wanting to do so? Above floor will respond, and maintain a given floor temp with lower temperature fluid. Lower temp fluid means less loss from boiler and associated plumbing for a given pipe insulation. Beyond that, not a lot of physical difference between above and below IMO.

I am planning to use a glue down floor and it strikes me that if ever anything happened to compromise the tubing, it would be nearly impossible to fix it without damaging the floor. I don't mind ripping out the ceiling if need be. It also seems less expensive and less intrusive. Lastly, I found that in areas near windows and doors, it was easy to do a double run with the staple up and get a great result.

I don't doubt that it would perform better on top of the sub-floor, but there is better and there is "good enough". In my current home, the system runs at under 100 degrees, I have an older condensing boiler (1990s) that does just fine, its always warm, and my bills are low.

Actually, I am a firm believer of placing PEX in a concrete slab when the building has a slab. I will also say that I prefer a polished or stamped concrete floor in lieu of a hardwood floor. A hardwood floor looks great on day one and thereafter becomes a maintenance issue to keep nice. I prefer putting nice looking wood where you don't walk on it...doors/windows, door/window trim, and base/crown moulding. I am not a fan of white painted particle board...

When you have a slab, hydronic radiant can be accomplished for less than any other heating approach. When you don't, mini splits almost always make more sense.

In order to get 90% of the radiant floor heat to flow up, you need ratio the R-value above/below the PEX accordingly. If the floor is a second story floor, this isn't as critical as the downward heat still stays in the building. A staple up will require at least 40-50% higher supply temp than a concrete slab at the same design indoor/outdoor temp.

I am planning to put PEX in the slab. The house will have a large below-grade basement that we plan to use as living space. The rest of the house will have hardwood parquet floors that glue to the sub-floor. I will have 2.5 stories, so I don't think I can count on the slab heat to radiate through the whole house.

No, just heating the basement slab will not get the job done. If you have a well-insulated and well-sealed home or live in a mild climate, the performance of your heating system becomes less critical. In other words, if there isn't much heat loss, there isn't much heat gain needed and reducing the cost by say 50% is still a small number. This is why improving the building envelope is always the best place to invest. We have free calculators on our website that would allow you to see the precise performance of the various hydronic heating emitter options. We also have calculators to estimate your monthly/annual heating expense for all heating system options.

The house is new construction. I will either build with SIPS or do prefab with walls based on the perfect wall concept. So, it will be a tight house. As such, I'm not worried right now about efficiency. My hope is to get implementation advice: best way to affix tubes, ideas for insulation, manifolds, type of PEX, etc.

I've only seen a couple of staple-up setups thus far.

All but one has been aluminum track, covered by a self-adhesive thermal barrier that's also tacked/stapled into place, and then insulated over (usually spray foam).

The one outlier simply used a thermally conductive self-adhesive fabric laid onto the under-floor, then used to secure the pex into place. Then the standard radiant barrier + insulation.