Renovating bedroom, flooring and joist issues

[justusandersson]

On the link, there is an image showing how gluing and screwing are done over a beam. It also states that longitudinal joints are made over noggings (which do not need to have the height of the beams). It also refers to the manufacturers' websites.

Siporex was a type of lightweight concrete (without radon) manufactured in Skåne.

 

[eddiw]

I first tried just screwing down the old floor to get rid of the creaking. It turned out to be ineffective. So, out with the old floor and in with new floor chipboard that was glued and screwed. Became completely silent. At the same time, you can take the opportunity to check the insulation. Remove all the debris (I learned the nice term "contractor's mix"). As new insulation, you could use fluffed cellulose, which feels more suitable for an older house.

Thanks for the info, then I feel like I'm thinking right =) I want to get rid of the creaking. So, the old plank floor and the debris between the beams have to go

 

[Lane]

Yes, exactly, they are very light and kind of with air bubbles in them. I can very well imagine that they can be drawn with
Maybe it's siporex then? However, nothing else in our house is built with that.

Not in our house either, we only have this in pieces under the floor and as larger blocks/bricks buried in the garden (one theory is that they crushed blocks themselves to lower the price, but I don't know, it was long before my time).

 

[eddiw]

On the link, there's an image showing how gluing and screwing occurs over a beam. It also states that longitudinal joints are made over noggings (which do not need to have the height of the beams). Then, they also refer to the manufacturers' websites.

Siporex was a type of lightweight concrete (without radon) that was manufactured in Skåne.

Hmm okay, so you should install noggings too then (meaning transverse battens?) at each longitudinal joint? If they don't need to be the same height as the beams, how are the joints supported then?
In many other places, the short sides are not mounted over beams, but I assume it becomes strong when glued?
Check here, for example; no noggings there as far as I can see and the floor panel is hanging in the air on the short sides here and there..

 

[justusandersson]

If you need to mount kortlingar (preferably 45x70), they should obviously be level with the beams. But first, check with the manufacturer of the floor chipboards that you plan to choose. I'm not entirely sure that kortlingar are needed.

 

[Thomas_Blekinge]

This with shortlings creates extra work. You first have to build two shortlings that will support the actual shortling that lies under the joint. Feels wrong.
Depending on how large the bedroom is, you can, with some adjustment, make it so that the joints always end up on a beam.

 

[eddiw]

This with crossbars causes extra work. You must first build two crossbars that will support the actual crossbar placed under the joint. It feels wrong. Depending on how big the bedroom is, you can, with a bit of fitting, manage it so that the joints always end up on a stud.

Yes, absolutely, you can cut the studs so that the joints end up over the studs, but that means cutting almost every board, instead of just laying them out. Admittedly, there won't be that many chipboards in a bedroom, they are quite large anyway.

 

[Limpan123]

Recently did the same thing in a room/bedroom, removed two layers of flooring. Leveled, added 22mm chipboard flooring. Depending on the boards you buy, you can have joints in the air. They are made for cc 60. And if you have less, it will just be sturdier. Double glue in the groove and on the joist. Feels sturdy despite cc70 in some places.

 

[eddiw]

Recently did the same thing in a room/bedroom, removed two layers of flooring. Leveled, applied 22mm chipboard. Depending on the boards you buy, you can have joints in the air. They are made for 60 cm centers. And if you have less, it will just be sturdier. Double glued in tongue and groove and on the joist. Feels sturdy despite 70 cm centers in some places.

Ok, yes the centers vary between 50 and 65 so it should work and be sturdy I think. By the way, what did you do when you leveled?

 

[eddiw]

75x175 mm, which corresponds to 3x7 inches is an option, 75x187, which corresponds to 3x7.5 inches is another. They only used inch measurements at that time. 4.4 meters is really too long a span, especially to limit the deflection. The best solution is to screw and glue a 22 mm chipboard (k-plywood also works well) onto the joists and then lay a new 14 mm wooden floor on top of this. Doing so will give you a floor that you will be satisfied with. Removing the slagstone and replacing it with a mineral wool board (not filling the entire space) reduces the load on the joists but has no effect on the deflection.

Correction:
I have now started working on the bedroom again and took some time to actually clear out the stones lying there. The beams were not 3x7 (75x185) but about 75x235. One beam is also 100x235 (for some reason).

The slagstone lies on a windpaper and under the windpaper, there is a layer of planks that freely rest on some edge strips on the beams. Not nailed, so they can be easily removed. Under that layer, there is another layer of planks, which I assume is the first ceiling of the lower floor (there is also wood paneling on the ceiling, which I assume sits on the original plank ceiling. However, there is a cavity between this and the slagstone. Should I remove the first planks and fill the entire space with new insulation, or is it enough to insulate the top layer? i.e., let the planks remain and keep the cavity below? In this case, it will be about 18 cm of insulation.

Thanks in advance.

 

[justusandersson]

75x235 mm (probably 3x9 1/2 inches) is much better. A screwed glued chipboard on top and you will be rid of sagging problems.

In the walls, you have plank, but hardly in the floor. Since they are probably not thick and wide enough, I would call them boards. We who are construction-damaged associate wrongly with the word plank. The top layer of boards is a sort of subfloor. I would probably remove them. Since the next layer of boards is likely nailed from below into the floor joists, I can't see that the cavity does any good. It is better to lay insulation directly against the lower layer of boards and have an airspace above. Do not fill the entire space with insulation.

 

[Limpan123]

Ok, yes, the cc measurements vary between 50 and 65 like that, so it should work and become stable, I think.
What have you done when you’ve straightened by the way?

I cut wedges the length of the room from 45mm timber. Varied from 2 to 5 cm in places. Screwed them down into hand-hewn ceiling beams, where it wasn't directly against the uneven beam, I put in different levels of masonite strips. The planed side up, so it became a good side to glue against.

Agree with justusandersson, place insulation on the bottom layer of boards. 70 or 95 thick is enough. If you have an outer wall, fill all the way up to the floor in the outermost compartment, or about 50cm out from the wall to prevent drafts.

 

[eddiw]

75x235 mm (probably 3x9 1/2 inches) is much better. A screwed chipboard on it and you're rid of the sway problem.

In the walls, you have plank, but hardly in the floor. Since they probably aren't thick and wide enough, I would call them boards. We who are construction damaged associate the wrong thing with the word plank. The top layer of boards is a kind of false bottom. I would probably remove them. Since the next layer of boards is probably nailed from underneath in the floor joists, I can't see that the cavity does any good. It's better to lay insulation directly against the lower layer of boards and have an air space above. Do not fill the entire compartment with insulation.

Thanks justusandersson and Limpan123 for great answers. I will probably remove the middle boards. justusandersson: The fact is that it actually seems to be plank in most places in the floor, they have the same dimensions as the wall. Some compartments only have boards, now I'm talking about the "false bottom" though..

So, of course, another question arises; Now that I'm shoveling away the slag stone, what insulation should I replace with? What is best to put in? Both in terms of sound and draft from the outer walls..

I'm going to go up and shovel more stone now....

 

[justusandersson]

Yes, a plank is a plank even when it's lying on the floor. I just wanted to advocate for some precision in word choice...

Medium-density mineral wool, with a volume weight of around 50 kg/cubic meter, is usually what's recommended as an airborne sound-reducing material. And do as Limpan123 suggests, fill along the outer walls.

 

[eddiw]

Yes, a plank is a plank even when it's on the floor. I just wanted to advocate for some precision in word choice...

Medium-heavy mineral wool, with a density around 50 kg/cubic meter, is generally recommended as a soundproofing material. And do as Limpan123 suggests, filling along the outer walls.

I understand, for a home tinkerer like me, it's not as apparent as it is for real craftsmen when you happen to name things incorrectly. Thanks for the enlightenment.

Hmm, you wouldn't happen to have a link to where you can find this? I checked various sites and only find lambda values and such listed... Like "Lambda 37" and that's more thermal conductivity... I can't find anything about 50kg/cubic meter? Can it be indicated in other ways? Sorry for the silly questions...