In the starting phase of building a split-level house (90 + 90 sqm). My question is whether it's worth the additional cost (~50,000
to cast the intermediate floor and install underfloor heating instead of going with a "traditional" floor structure with radiators on the upper floor. What are the pros and cons?
The ground floor is a slab with brick-leca walls and two brick load-bearing walls.
Advantages that I can imagine are:
- comfortable with underfloor heating
- quieter house (no footstep noise on the lower floor)
- less moisture-sensitive floor structure (having a bathroom on the upper floor)
I appreciate any experiences and other reflections on cast floors versus "traditional" floor structures.
to cast the intermediate floor and install underfloor heating instead of going with a "traditional" floor structure with radiators on the upper floor. What are the pros and cons? The ground floor is a slab with brick-leca walls and two brick load-bearing walls.
Advantages that I can imagine are:
- comfortable with underfloor heating
- quieter house (no footstep noise on the lower floor)
- less moisture-sensitive floor structure (having a bathroom on the upper floor)
I appreciate any experiences and other reflections on cast floors versus "traditional" floor structures.
Certainly, a cast floor structure results in a quieter floor. Underfloor heating works just as well (if not better) in a timber floor structure. The moisture sensitivity is probably the opposite; concrete is more moisture-sensitive.
These were some comments on your post and I will of course clarify a bit.
That the floor structure becomes quieter is simply a fact, it's just how it is, period. Underfloor heating works excellently in concrete, but also in a timber floor structure. Concrete has the advantage that it is a very heavy mass that heats up and retains the heat for a long time. The disadvantages include that with weather changes, concrete is significantly slower, so if it gets cold quickly, it can be difficult to heat up in time, and vice versa if it turns warm, it can easily become TOO warm indoors. In this way, the timber floor structure is better with heat distribution plates, etc. However, if you plan to have tiles as a surface layer, I would choose concrete, since wood is always wood and it moves a little bit with the seasons. Regarding moisture sensitivity, it is the case that the moisture barrier in the bathroom is equally important in both cases. But if you get a leak through the moisture barrier with a timber floor structure, you will see it after a couple of days at most, whereas in the concrete floor structure, it takes a couple of months, and by then the moisture has probably spread widely in the floor structure, and it's just a matter of tearing out the mats and drying almost the entire intermediate floor structure.
So there are both pros and cons. Another thing to consider is that a concrete floor structure is heavy. 90 m2 weighs approximately 22 tons, compared to a timber floor structure which may weigh 1.5 tons. So the foundation at the bottom must be dimensioned for that pressure.
Some viewpoints from:
Tartan
These were some comments on your post and I will of course clarify a bit.
That the floor structure becomes quieter is simply a fact, it's just how it is, period. Underfloor heating works excellently in concrete, but also in a timber floor structure. Concrete has the advantage that it is a very heavy mass that heats up and retains the heat for a long time. The disadvantages include that with weather changes, concrete is significantly slower, so if it gets cold quickly, it can be difficult to heat up in time, and vice versa if it turns warm, it can easily become TOO warm indoors. In this way, the timber floor structure is better with heat distribution plates, etc. However, if you plan to have tiles as a surface layer, I would choose concrete, since wood is always wood and it moves a little bit with the seasons. Regarding moisture sensitivity, it is the case that the moisture barrier in the bathroom is equally important in both cases. But if you get a leak through the moisture barrier with a timber floor structure, you will see it after a couple of days at most, whereas in the concrete floor structure, it takes a couple of months, and by then the moisture has probably spread widely in the floor structure, and it's just a matter of tearing out the mats and drying almost the entire intermediate floor structure.
So there are both pros and cons. Another thing to consider is that a concrete floor structure is heavy. 90 m2 weighs approximately 22 tons, compared to a timber floor structure which may weigh 1.5 tons. So the foundation at the bottom must be dimensioned for that pressure.
Some viewpoints from:
Tartan
Thank you for your feedback!
- I read somewhere in the forum that leca walling "benefits" from being heavily loaded because the load prevents it from moving as much. This would, according to claims, lead to fewer cracks in the external plastering (in our case, slamming).
- I have also heard that underfloor heating in a wooden joist can dry out the wood, which under certain conditions can lead to "squeaking" sounds when walking on the floor.
- There will be a heated slab on the ground floor, which will provide a relatively slow heating system. The alternative in our case is to have waterborne radiator heating on the upper floor and complement it with electric underfloor heating in the bathroom and entrance. With a cast slab, hopefully, the entire house will be more harmonious. That is, just one large slow heating system. Instead of a combination of a fast and a slow one.
But this is just what I've heard and I'm no expert, so I really appreciate all the contributions to the debate.
- I read somewhere in the forum that leca walling "benefits" from being heavily loaded because the load prevents it from moving as much. This would, according to claims, lead to fewer cracks in the external plastering (in our case, slamming).
- I have also heard that underfloor heating in a wooden joist can dry out the wood, which under certain conditions can lead to "squeaking" sounds when walking on the floor.
- There will be a heated slab on the ground floor, which will provide a relatively slow heating system. The alternative in our case is to have waterborne radiator heating on the upper floor and complement it with electric underfloor heating in the bathroom and entrance. With a cast slab, hopefully, the entire house will be more harmonious. That is, just one large slow heating system. Instead of a combination of a fast and a slow one.
But this is just what I've heard and I'm no expert, so I really appreciate all the contributions to the debate.
If underfloor heating loops were included, it was an OK price (50,000), otherwise not. This should be compared to the case of wooden joists with insulation, floorboards, loops, plates.
If you have children who will be running upstairs, it might be worth investing in a quieter floor, but there are other ways to achieve that too. If you're going to use the upper floor as bedrooms, it doesn't matter.
If I could choose again, I would choose heating loops on my upper floor with wooden joists. Visible radiators are quite ugly.
/CC
If you have children who will be running upstairs, it might be worth investing in a quieter floor, but there are other ways to achieve that too. If you're going to use the upper floor as bedrooms, it doesn't matter.
If I could choose again, I would choose heating loops on my upper floor with wooden joists. Visible radiators are quite ugly.
/CC
We received a quote of 30,000 for 90 sqm. An advantage of having underfloor heating loops on the upper floor, which must be considered, is that you can have the same temperature for the supply water both upstairs and downstairs. If you have different systems in the house, you must adjust the temperature in the heat pump to the level of the radiators, which is about 10° higher, and this is uneconomical. You also have to mix down the temperature in the loop because otherwise, the supply water to the loop on the ground floor would be too warm. The mixing valve (if it's spelled that way, I'm not a plumber) isn't cheap either.
We chose radiators on the upper floor because it was too much trouble to remove all the boxes and other clutter from the entire floor area, as our unfinished attic had become a storage space. :-/
Most people choose radiators, and I don't understand why. Don't be fooled by those who say, "The floor will still be warm because it heats from the ground floor."
/CC
We chose radiators on the upper floor because it was too much trouble to remove all the boxes and other clutter from the entire floor area, as our unfinished attic had become a storage space. :-/
Most people choose radiators, and I don't understand why. Don't be fooled by those who say, "The floor will still be warm because it heats from the ground floor."
/CC