It is time for me to join the forum as a writer and not just a reader now that I have finally become a homeowner 
I have read the forum but cannot find an answer to my question (although I have received a lot of help regarding sound from posts by Zankan).
To the question:
I want to soundproof between the ground floor and the finished basement floor, previously you could stand in both rooms and have a conversation in a normal tone between the floors!
We then thought of taking up the floor to see what might be between them (mostly air, we thought).
But the floor was filled with wood shavings (220mm).
The following is a simple description:
(The house is from 1957, wood)
about 220mm joists cc 600
25mm pine floor directly nailed to the joists
On the underside, a masonite board is nailed and under this, a sparse panel that acts as the ceiling for the basement.
No radiator pipes run between the floors (they go down into the joist) so I have no direct holes between the rooms.
As we only have 202cm of ceiling height in the basement, I would prefer not to work from that direction.
The plan is as follows:
Remove >100mm of the wood shavings and insert foundation board (likely Paroc GRS20, maybe GRS30) and leave some air to the top of the joist.
On the joist, I thought of laying some form of damping (epdm or another strip).
Then I would like a dead material (compact) and thereby lay floor gypsum (13mm), the floor gypsum would be soft sealed against the walls to make it completely tight.
Then a grooved chipboard 13mm for hydronic underfloor heating. (also soft sealed?)
(Then an intermediate layer according to the building code, not yet decided which material to choose here, trying to find one with good thermal conductivity)
On top of this, 14mm parquet.
I would rather not put the gypsum on top of the chipboard as it would be 27mm for the underfloor heating to work (Am I thinking right/wrong?)
How should I then attach the gypsum boards to the joist, is it enough to screw (of course with the correct screws for floor gypsum) directly into the joist? Since I lay chipboard on top, creeping screw heads shouldn't be a problem?
How should I attach the chipboard to the gypsum? Can it be laid loose or should it be glued or screwed?
The problem with starting to glue is that I feel it might be better to just put a 25mm thick chipboard directly against the joist and then parquet, however, I would like to include a gypsum layer for its dampening effect.
We are looking to deaden airborne sound, not impact sound (footstep sound is completely okay).
I have read the forum but cannot find an answer to my question (although I have received a lot of help regarding sound from posts by Zankan).
To the question:
I want to soundproof between the ground floor and the finished basement floor, previously you could stand in both rooms and have a conversation in a normal tone between the floors!
We then thought of taking up the floor to see what might be between them (mostly air, we thought).
But the floor was filled with wood shavings (220mm).
The following is a simple description:
(The house is from 1957, wood)
about 220mm joists cc 600
25mm pine floor directly nailed to the joists
On the underside, a masonite board is nailed and under this, a sparse panel that acts as the ceiling for the basement.
No radiator pipes run between the floors (they go down into the joist) so I have no direct holes between the rooms.
As we only have 202cm of ceiling height in the basement, I would prefer not to work from that direction.
The plan is as follows:
Remove >100mm of the wood shavings and insert foundation board (likely Paroc GRS20, maybe GRS30) and leave some air to the top of the joist.
On the joist, I thought of laying some form of damping (epdm or another strip).
Then I would like a dead material (compact) and thereby lay floor gypsum (13mm), the floor gypsum would be soft sealed against the walls to make it completely tight.
Then a grooved chipboard 13mm for hydronic underfloor heating. (also soft sealed?)
(Then an intermediate layer according to the building code, not yet decided which material to choose here, trying to find one with good thermal conductivity)
On top of this, 14mm parquet.
I would rather not put the gypsum on top of the chipboard as it would be 27mm for the underfloor heating to work (Am I thinking right/wrong?)
How should I then attach the gypsum boards to the joist, is it enough to screw (of course with the correct screws for floor gypsum) directly into the joist? Since I lay chipboard on top, creeping screw heads shouldn't be a problem?
How should I attach the chipboard to the gypsum? Can it be laid loose or should it be glued or screwed?
The problem with starting to glue is that I feel it might be better to just put a 25mm thick chipboard directly against the joist and then parquet, however, I would like to include a gypsum layer for its dampening effect.
We are looking to deaden airborne sound, not impact sound (footstep sound is completely okay).
Wood shavings are usually not that bad as airborne sound insulation. There must be another catch. Your intended soundproofing will probably work. Adding damping on the floor joists is mostly done to reduce impact noise. 13 mm grooved chipboard + 14 mm parquet feels a bit flimsy. I don't believe in the idea of laying floor gypsum without a base. The question is, what is most important to achieve?
I agree that wood shavings shouldn't be that bad, I will crawl around and see if I can find more.
To provide a better explanation of the room:
Square room with a wardrobe wall (which I have now removed)
The walls are as follows: outer wall, outer wall, wardrobe wall with a 1.2m inner wall, inner wall towards the bathroom (the latter also contains the door to the hallway)
Directly below is the other bedroom, but the wardrobe wall is above another room in the basement (which doesn't have the same sound problem).
This means the wardrobe cannot be the issue.
The doors are almost placed above each other, and I'm considering removing the threshold to see if there's a cavity there.
(However, you can't hear anything if you're standing in the basement hallway outside the room, which makes me doubt the threshold is the problem)
The basement is a poured foundation (1957) so not hollow walls (as far as I believe).
The inner walls in the upper bedroom are masonite with vertical boards behind (unclear what's in between, it's the next step to investigate, but I prefer not to break open the inner wall, especially not the one towards the bathroom).
If we go back to my construction, I have 50mm to build on.
It's leaning towards us choosing LK's system with a 22mm grooved chipboard so that we have a component that is fully supportive, I'll send them an email today asking about having 13mm gypsum + 14mm parquet on top.
(It doesn't feel optimal because the risk is that the heat then goes downwards)
That's why I'd prefer to have the gypsum under the chipboard.
We have the option to lay 13mm gypsum, 22mm chipboard, 14mm parquet.
But here I'm unsure about the fastening of the joists to the gypsum and gypsum to chipboard.
(Hence the thread).
It feels like the simplest solution is to use 22mm chipboard (soft-sealed) + 14mm parquet and hope that's enough, but I'd like to hear from someone with experience.
To provide a better explanation of the room:
Square room with a wardrobe wall (which I have now removed)
The walls are as follows: outer wall, outer wall, wardrobe wall with a 1.2m inner wall, inner wall towards the bathroom (the latter also contains the door to the hallway)
Directly below is the other bedroom, but the wardrobe wall is above another room in the basement (which doesn't have the same sound problem).
This means the wardrobe cannot be the issue.
The doors are almost placed above each other, and I'm considering removing the threshold to see if there's a cavity there.
(However, you can't hear anything if you're standing in the basement hallway outside the room, which makes me doubt the threshold is the problem)
The basement is a poured foundation (1957) so not hollow walls (as far as I believe).
The inner walls in the upper bedroom are masonite with vertical boards behind (unclear what's in between, it's the next step to investigate, but I prefer not to break open the inner wall, especially not the one towards the bathroom).
If we go back to my construction, I have 50mm to build on.
It's leaning towards us choosing LK's system with a 22mm grooved chipboard so that we have a component that is fully supportive, I'll send them an email today asking about having 13mm gypsum + 14mm parquet on top.
(It doesn't feel optimal because the risk is that the heat then goes downwards)
That's why I'd prefer to have the gypsum under the chipboard.
We have the option to lay 13mm gypsum, 22mm chipboard, 14mm parquet.
But here I'm unsure about the fastening of the joists to the gypsum and gypsum to chipboard.
(Hence the thread).
It feels like the simplest solution is to use 22mm chipboard (soft-sealed) + 14mm parquet and hope that's enough, but I'd like to hear from someone with experience.
LK states in their design guidelines that the floors should be fully insulated. So your idea of leaving some air above the insulation is not something they recommend.
"Underfloor heating in timber joists There are many different solutions for underfloor heating in timber joists such as grooved floorboards, joist plates, and dispersed panel installation. In general, joist cavities should be fully insulated and sealed to prevent heat from being 'ventilated' away. It is important that the insulation sits against the underside of the underfloor heating."
See page 10 in the document below.
http://www.lksystems.se/globalassets/inriver/resources/se.33.b.1_projekteringsanvisning.pdf
"Underfloor heating in timber joists There are many different solutions for underfloor heating in timber joists such as grooved floorboards, joist plates, and dispersed panel installation. In general, joist cavities should be fully insulated and sealed to prevent heat from being 'ventilated' away. It is important that the insulation sits against the underside of the underfloor heating."
See page 10 in the document below.
http://www.lksystems.se/globalassets/inriver/resources/se.33.b.1_projekteringsanvisning.pdf
Functionally, there are no issues with having air space between the wood chips and the subfloor if you want the latter to be as close to the underfloor heating as possible.
I can sketch out what a basement in a house from 1957 looks like in my sleep. The outer walls are certainly made of hollow concrete blocks, as are most of the interior walls. Lightweight concrete may occur in smaller sections. The walls rest on concrete footings, and between the walls, there is a thin unreinforced (often plastered) concrete slab that has been cast afterwards. There is no chance that the basement construction contributes to unwanted sound transmission. The "holes" must be sought in the floor structure.
I can sketch out what a basement in a house from 1957 looks like in my sleep. The outer walls are certainly made of hollow concrete blocks, as are most of the interior walls. Lightweight concrete may occur in smaller sections. The walls rest on concrete footings, and between the walls, there is a thin unreinforced (often plastered) concrete slab that has been cast afterwards. There is no chance that the basement construction contributes to unwanted sound transmission. The "holes" must be sought in the floor structure.
Thanks for the great tips.
The sound is an ongoing investigation and search, but it's a separate topic.
What I'm mainly wondering is how I should attach floor gypsum to joists and gypsum to chipboard.
Alternatively, I could place the gypsum on top of the chipboard but would prefer to avoid this.
(LK has mentioned that it is okay to lay gypsum + 14mm parquet on top of the underfloor heating)
The sound is an ongoing investigation and search, but it's a separate topic.
What I'm mainly wondering is how I should attach floor gypsum to joists and gypsum to chipboard.
Alternatively, I could place the gypsum on top of the chipboard but would prefer to avoid this.
(LK has mentioned that it is okay to lay gypsum + 14mm parquet on top of the underfloor heating)
You cannot place floor gypsum directly on the studs. If you don't want any sheet material underneath, you must use some form of sparse paneling or noggins.
Many thanks for a construction-wise answer.
It definitely puts a spanner in the works for the construction (and why I couldn't google how to do it).
The building height becomes too much if we apply furring strips+drywall+particleboard+flooring.
The remaining choice is whether to have drywall on top of the particleboard or simply build without drywall.
(I would prefer to avoid glue that is not white glue for the particleboard)
It definitely puts a spanner in the works for the construction (and why I couldn't google how to do it).
The building height becomes too much if we apply furring strips+drywall+particleboard+flooring.
The remaining choice is whether to have drywall on top of the particleboard or simply build without drywall.
(I would prefer to avoid glue that is not white glue for the particleboard)
Nogging pieces do not affect the construction height, but there will be a lot of sawing. It is fine to use 45x70 for nogging pieces.
You are absolutely right, but yes, there will be a lot of sawing
If I install cross battens and plan to install plasterboard + particleboard, I suspect I'll be forced to glue the particleboard to the plasterboard?
Or is it possible to screw it here as well? It feels like glue is the way to go to get it right.
(Of course, the correct glue should be used, there are enough threads about that. I would prefer to avoid glue, though.)
If I install cross battens, it gets a bit trickier with insulation and making it airtight, but who said renovating was supposed to be easy.
If I install cross battens and plan to install plasterboard + particleboard, I suspect I'll be forced to glue the particleboard to the plasterboard?
Or is it possible to screw it here as well? It feels like glue is the way to go to get it right.
(Of course, the correct glue should be used, there are enough threads about that. I would prefer to avoid glue, though.)
If I install cross battens, it gets a bit trickier with insulation and making it airtight, but who said renovating was supposed to be easy.
There are two situations when it is important to glue. Firstly, a floor particle board against the joists when the particle board needs to interact with them to achieve sufficient stiffness in the floor. Secondly, a gypsum board against the underlying particle board or plywood when tiles are to be laid on top (otherwise, the joints will not hold). In your case, I find it difficult to see any point in doing so.
So if I interpret your text correctly:
If I make noggins and screw in a plasterboard, should I also be able to screw in the chipboard?
Since I am adding noggins, the floor should then be stiff enough without needing glueing.
Of course, the chipboard should be glued individually to each other according to the supplier’s installation instructions.
It's the first house, so I gratefully accept all the knowledge available, especially since floors and joists are not something I've worked with before. (except laying click floors on existing floors)
If I make noggins and screw in a plasterboard, should I also be able to screw in the chipboard?
Since I am adding noggins, the floor should then be stiff enough without needing glueing.
Of course, the chipboard should be glued individually to each other according to the supplier’s installation instructions.
It's the first house, so I gratefully accept all the knowledge available, especially since floors and joists are not something I've worked with before. (except laying click floors on existing floors)
You can't express it that way. Noggins can affect the deflection by redistributing point loads, but it doesn't affect sagging. This is an aspect we haven't discussed, the need for stiffening your floor. To see if there is a need for it, I need to know the length, cross-sectional dimensions, and c/c spacing of the floor joists.T Truant said:
The sound problem is most likely the combination of fiberboard in the basement ceiling (3 mm?) and wooden floorboards. This means there are plenty of gaps for the sound to travel through, and thin fiberboard doesn't stop sound very well precisely because it is thin. So a regular chipboard floor sealed at the edges and any penetrations should do the trick. Don't overcomplicate it. Perhaps there are even thicker chipboard floors that are grooved for underfloor heating?