ᐅ Solid wood parquet on underfloor heating

Let’s keep it simple. Yes, it’s better to glue down the parquet flooring because otherwise, the impact sound insulation/air gap acts as insulation. Potentially, this could cause slightly more heat loss downwards since the heat doesn’t rise as easily.

BUT: In real life, you won’t be able to measure whether the parquet is glued down or floating. Opening the windows three times has a much bigger effect on energy consumption.

BUT: Glued parquet sounds more solid when walking on it because it’s firmly attached to the subfloor. That alone is reason enough to glue down the parquet. I couldn’t care less about saving 50 cents a month on heating costs 😉

Tolentino schrieb:

So, you mean that with a fixed supply temperature and a fixed room temperature, the indoor temperature with an air gap will always be lower than without, no matter how long you wait?

Correct!

(Obvious limitation: supply temperature < room temperature < return temperature and the pump’s flow rate must remain the same.)

Tolentino schrieb:

Where does the energy go then?

It stays in the water; in other words, the return temperature is higher.
(or it dissipates into the floor slab, but that’s probably a rather small effect).
Now one might say, well, if the energy stays inside, then no additional consumption arises.
The point is that we have to increase the supply temperature to reach the desired room temperature.
This leads to higher losses and the heating system (especially the heat pump) operates less efficiently.

ateliersiegel schrieb:

If it’s in the warm heating pipe, it wants to move into the cold room.

And that is exactly what some floor coverings and installation methods make more difficult.

ateliersiegel schrieb:

The faster heat escapes from the room through the exterior wall, the faster you have to heat to prevent the indoor temperature from dropping.
If heat moves from the heating pipe into the room as fast (or faster) as it moves from the room outside, then everything should be “fine.”

Fast and slow are somewhat tricky terms here.
But fundamentally correct. Again, certain floor coverings reduce heat transfer, so to maintain the same “speed” you need to increase the supply temperature.

Benutzer200 schrieb:

I couldn’t care less about saving 50 cents a month on heating costs 😉

Basically true. But if this is a topic of discussion, it should be answered properly without dismissing it as mere inertia.
Depending on the floor covering and installation method, supply temperatures can differ by several degrees.
It is commonly said that heating consumption increases by about 2.5% per degree of supply temperature rise. Whether that is relevant for you personally is something everyone can decide, informed.
I just find it odd when the pipe spacing is calculated and optimized down to the last detail, but the floor covering is suddenly considered irrelevant, even though differences in thermal transfer between tile and vinyl versus parquet and carpet can vary by a factor of ten.

@DaSch17 As I understand you, you prefer floating installation because you want to do it yourself and don’t want a completely hard floor, a so-called resilient floor 😀.

The most important thing is that you’ve heard from various professionals that you can do it either way, and neither is a major mistake. So, I would go with the method I can confidently carry out myself, because for me, it’s important to do it myself and it would be enjoyable.

You can approach this (any) topic from many perspectives, here recently from the aspect of temperature, etc. You could also reason it based on the unused adhesive in your home; in my opinion, there’s no absolute right or wrong. However, since the forum is very (sometimes too) technically and calculation-focused, it might be that just the math regarding the effect of your underfloor heating would push you toward gluing. But then what do you tell the person who explains exactly how problematic the large amounts of adhesive are that your family might end up inhaling?

Therefore, I would do what suits me better, and for me that would definitely be floating installation. The statement earlier that the other option is “better” seems too general to me, because it always depends on what you want to achieve.

We lived until November 2021 on about 200 sq. meters (2,150 sq. feet) of floating-installed high-quality parquet flooring (second choice/first-class quality). I honestly can’t think of anything that should have bothered me about it. Underneath was underfloor heating, and between was the insulation material with an aluminum foil layer.

Like every product or installation method, each has advantages and disadvantages; you should simply determine which you prefer.

For us, gluing was not an option because I would never sand finished oak parquet!!! Why would I? We lived with a dog on pine floorboards and didn’t sand those either, and I also didn’t want large amounts of adhesive in the house.

You just need to realize that wood is wood with all its properties, but not everyone wants that, which is why there are, for example, tiles with wood appearance—a contradiction I don’t understand, like vegan sausage.

My son lives on glued parquet, and I find it extremely hard, as if walking on tile, which I don’t like.

With floating installation, the floor doesn’t actually float or swing; it lies perfectly flat on the subfloor. It’s also additionally weighted by furniture and so on. If you drop something, it’s not immediately damaged as it would be on a hard glued floor, and it just feels much softer to walk on than glued flooring. Anyway, I find the idea of gluing wood onto cement kind of strange, but that’s just a feeling I have.

Here in our house, for example, we have screwed-down plank flooring, and the joists underneath are all installed floating. We probably could have screwed those down too, but I liked that idea, and it works quite well. Yes, sometimes it creaks or gaps change, but for heaven’s sake, it’s a natural product I want, so how could I object to it showing its nature this way?

With the high-quality parquet, we sometimes heard a walking noise in one room that sounded like it came from the aluminum foil underneath. It never bothered us, but for underfloor heating temperature, I’d choose an underlay without this aluminum foil, though I really find these micro-details unnecessary.

I was aware of the expansion gap, but we were fairly “bold” about it. I would consider whether to intentionally create something nice out of this requirement, like installing part of the floor in a different direction or placing a stylish carpet or tiles where it fits. Let your imagination run or use a nice metal strip where it makes sense.

For me, with tiles, I also like to see a grout line just as I accept knots or the occasional creak in wood; I’m not a fan of the popular practice of forcing materials to conform to my ideas by ignoring their natural characteristics.

Ok, if that’s the case, you’ve convinced me. But then I wonder why this doesn’t actually matter in the heating load calculation. At least in mine, it didn’t make a difference whether I specified laminate or tiles. And here we are even talking about the same floor covering (maybe even the identical one) and just an air gap that is probably less than 1mm (0.04 inches) thick.

ateliersiegel schrieb:

Where there is insulation, it moves slowly; where there is a good heat conductor, it moves faster.

With good insulation, it doesn't move at all. For example, consider an electrical cable.
Basically, it’s not about speed, but about the amount of energy transferred. Because steel transfers a lot of energy, a radiator feels hot faster.
However, it simply transfers more energy from the heating water to the air. An insulated floor cools down on the surface faster than energy can come from below. This is because the energy is not slower but less. In the worst case, the energy is insufficient.

Tolentino schrieb:

Okay, if that’s the case, you’ve convinced me. But then I wonder why it doesn’t actually matter in the heating load calculation. At least in mine, it made no difference whether I specified laminate or tiles.

The floor covering doesn’t affect the "load" itself.
It influences the input data. So it definitely has an impact on the design of the underfloor heating system and is taken into account there.
Usually, for simplicity and due to limited precise data, only the distinction between tiles and wood flooring is made.