ᐅ Subfloor Construction Without Screed for Solid Wood Planks – Experiences
Created on: 9 Nov 2020 19:04
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pagoni2020
My current plan is to have a standard concrete slab under the house; additional insulation is still possible.
Based on my experience with a house that has a basement, I had planned to lay a membrane on the raw subfloor (this time without a basement) as a moisture barrier. On top of that, I would install a joist or cross beam structure with loose-fill insulation in between (cork, perlite, hemp-light clay loose-fill; this is also what the contractor recommended).
I recently consulted a specialist company for these types of insulation materials, and they raised some concerns that the membrane on the raw subfloor might prevent moisture—potentially settling from indoor air in the worst case, through the wooden floorboards and insulation—from properly draining downward because of the membrane.
Their advice was to lay the joists directly on the membrane to protect the wood from direct contact with concrete and moisture, and to place the insulation directly on the raw subfloor instead.
In my opinion, however, this approach might carry the risk that residual moisture could rise from below into the insulation area, just reversing the problem.
One possible solution could be to use foam glass gravel when the concrete slab is first poured; however, I am not sure if my general contractor will implement this or if it actually makes sense.
I thought I had this issue figured out, but since there is no basement under the living areas in this build, it is making me reconsider. Ultimately, I want to avoid screed specifically because of moisture concerns.
Does anyone have more detailed experience or knowledge about this?
@Steffi33, you have a construction like this; could you share your exact setup (membrane, insulation, etc.)? Do you have a basement? What type of concrete slab do you have? What joist height did you use? Sorry for all the questions.
Based on my experience with a house that has a basement, I had planned to lay a membrane on the raw subfloor (this time without a basement) as a moisture barrier. On top of that, I would install a joist or cross beam structure with loose-fill insulation in between (cork, perlite, hemp-light clay loose-fill; this is also what the contractor recommended).
I recently consulted a specialist company for these types of insulation materials, and they raised some concerns that the membrane on the raw subfloor might prevent moisture—potentially settling from indoor air in the worst case, through the wooden floorboards and insulation—from properly draining downward because of the membrane.
Their advice was to lay the joists directly on the membrane to protect the wood from direct contact with concrete and moisture, and to place the insulation directly on the raw subfloor instead.
In my opinion, however, this approach might carry the risk that residual moisture could rise from below into the insulation area, just reversing the problem.
One possible solution could be to use foam glass gravel when the concrete slab is first poured; however, I am not sure if my general contractor will implement this or if it actually makes sense.
I thought I had this issue figured out, but since there is no basement under the living areas in this build, it is making me reconsider. Ultimately, I want to avoid screed specifically because of moisture concerns.
Does anyone have more detailed experience or knowledge about this?
@Steffi33, you have a construction like this; could you share your exact setup (membrane, insulation, etc.)? Do you have a basement? What type of concrete slab do you have? What joist height did you use? Sorry for all the questions.
Yes, we don’t have screed, but we also don’t have concrete ceilings; instead, we always have wood, even for the basement floor (since our basement is wooden). On the wooden ceiling, there are these green mats for insulation and protection, and on top of them, lime sandstone blocks were simply laid down (to prevent vibration and for sound insulation). The only exception is the pipes for ventilation and wastewater that run in the floor. For those, the dry screed panels (KSS) were removed, the pipes were installed, and then concrete was poured there.
On top of the dry screed panels, these green mats were placed again, followed by the panels for the underfloor heating, which were laid into a kind of “wooden framework.” Then the solid wood parquet flooring was installed, left natural at first, and later oiled:
Here you can see the openings left in the dry screed panels for the pipes – and underneath, the green mats resting on the wooden floor
Then the pipes were embedded in concrete:
And that’s really the only concrete we have in the entire house!
After that, those mats were laid again:
And this is how it looked with the mats for the underfloor heating:
Surely there are also nice insulation materials available without the loops for the underfloor heating
It looks like this over a large area:
And on top of that came the solid wood parquet:
Initially left natural:
Then oiled:
On top of the dry screed panels, these green mats were placed again, followed by the panels for the underfloor heating, which were laid into a kind of “wooden framework.” Then the solid wood parquet flooring was installed, left natural at first, and later oiled:
Then the pipes were embedded in concrete:
After that, those mats were laid again:
And this is how it looked with the mats for the underfloor heating:
It looks like this over a large area:
And on top of that came the solid wood parquet:
Initially left natural:
Then oiled:
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pagoni202011 Nov 2020 23:46haydee schrieb:
Whoever climbs will eventually fall. Considering what she and her best friend climb on or play with, I’m surprised nothing worse has happened. Our neighbor has said several times, “Today I prepared some plaster, just as a precaution.”
Great that you found what you were looking for.
When will you start building? The building permit / planning permission is expected any day now.......
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pagoni202012 Nov 2020 00:13Steffi33 schrieb:
How and where do you actually install your heating and water pipes with Steico/Gutex?We don’t have any heating pipes, and the water pipes are minimal since the ground floor bathroom is right next to the utility room, the upstairs bathroom is directly above the utility room, and the kitchen is also next to the utility room. I was told that you can partially recess my 6cm (2.4 inch) panels, or maybe I’ll create some kind of channel that I can then insulate with loose fill. But those are details I need to look into further first. Still, it’s a valid question.P
pagoni202012 Nov 2020 00:17Climbee schrieb:
Yes, we don’t have screed, but also no concrete ceilings; we always use wood, including for the basement floor (we have a wooden basement). On the wooden ceiling there are green mats for insulation and protection, and on top of those, calcium silicate bricks were simply laid (to prevent vibrations and for sound insulation). The only exception are the pipes for ventilation, wastewater, etc., which run in the floor. There, the KSS panels were removed, the pipes laid, and then concrete was poured.
On top of the KSS panels came those green mats again, and then the panels for the underfloor heating, which were basically laid into a "wooden frame." On top of that, natural hardwood flooring was installed and then oiled:
[ATTACH alt="IMG_20190411_184301.jpg"]53433[/ATTACH] Here you can see the openings left in the KSS panels for the pipes – and below them, the green mats resting on the wooden floor.
Then the pipes were embedded in concrete:
[ATTACH alt="IMG_20190503_152849.jpg"]53434[/ATTACH] And that is really the only concrete we have in the house!
On top of that came these mats again:
[ATTACH alt="IMG_20190604_210123.jpg"]53436[/ATTACH]
This is what it looked like with the mats for the underfloor heating:
[ATTACH alt="IMG_20190524_162109.jpg"]53435[/ATTACH] Surely, there are also good insulation materials without the loops for underfloor heating.
This is how it looks over a large area:
[ATTACH alt="IMG_20190606_154338.jpg"]53437[/ATTACH]
Then natural solid hardwood flooring was installed:
[ATTACH alt="IMG_20190608_110803.jpg"]53438[/ATTACH]
First natural:
[ATTACH alt="IMG_20190612_172041.jpg"]53439[/ATTACH]
Then oiled:
[ATTACH alt="IMG_20190615_093104.jpg"]53440[/ATTACH]Thanks for the great photos. That’s exactly how we want it, just without underfloor heating. The floor system will be the same, and in your case, a kind of duct for the supply lines was also left free.Similar topics