We live in a split-level house from 1943 where we are currently furnishing the basement. We have chipped out the floor, installed water-based underfloor heating, and cast a new floor. We have now reached the walls. Half of the house is above ground and half is below ground level. We understand that the walls below ground level need to be plastered. However, we are now wondering if we can place drywall directly on the hollow concrete blocks on the walls that are above ground. The walls were previously plastered, but we would like to put drywall on them if possible.
//Petra
//Petra
Here is my thread about gluing plasterboard to Leca, NOTE that this applies to interior walls!
https://www.byggahus.se/forum/threads/hur-limma-gips-mot-lecavaegg.41593/
I personally would NOT glue to the outer wall due to potential moisture issues and instead suggest:
https://www.byggahus.se/forum/threads/hur-limma-gips-mot-lecavaegg.41593/
I personally would NOT glue to the outer wall due to potential moisture issues and instead suggest:
- Frame up 45 mm metal stud against outer walls (now you have room for electrical wiring, etc.)
a) Above ground can insulate and add plastic
b) Below ground no internal insulation (this should be on the outside Pordrän/Isodrän), no plastic - Optional OSB/Plyfa to make it easier to screw/nail things to the walls
- Plasterboard
We also have a souterrain house. However, it is from -79 and therefore has furring strips on the inside. We are now putting Pordrän on the outside, and I am considering replacing the furred walls with metal studs and insulation above ground as previously suggested on the forum. We haven't had any problems yet, so it will be when the rooms downstairs need to be renovated at some point in the future.
A question though: It feels like you might get the "bongo drum effect" if you put boards on metal studs without insulation, or is there a smart way to get around that?
A question though: It feels like you might get the "bongo drum effect" if you put boards on metal studs without insulation, or is there a smart way to get around that?
Hmm now there are some mixed messages here... No organic, but yet people are advocating OSB very strangely. I mean, there is also something called ground moisture, but oh well. Personally, I would probably put 30 cm of plasterboard at the bottom.... Alternatively minerit...
And gypsum too! Stachybotrys chartarum a.k.a. paper mold a.k.a. black mold requires cellulose for nutrition and will thus thrive on the back of the gypsum..mr Z said:
I would go for a 45 mm metal stud (stabilized with metal angles against the outer wall) with mineral board as cladding.
Stop, stop......
Gypsum
OSB (if desired)
Plastic (only above ground)
Insulation (only above ground)
Leca
Plaster
Pordrän (below ground)
Panel (above ground)
If gypsum/OSB were to mold, wouldn't it do so regardless of the wall construction? I can attest that I have stored both OSB/gypsum leaned against a Leca wall for ~18 months and of course there is no black mold on it!
Can someone explain how this could happen?
Sure, ground moisture exists for those who don't have insulation under the slab. However, gypsum/OSB or similar should never stand directly on the slab. Place a temporary spacer first when you screw the boards up.
Gypsum
OSB (if desired)
Plastic (only above ground)
Insulation (only above ground)
Leca
Plaster
Pordrän (below ground)
Panel (above ground)
If gypsum/OSB were to mold, wouldn't it do so regardless of the wall construction? I can attest that I have stored both OSB/gypsum leaned against a Leca wall for ~18 months and of course there is no black mold on it!
Can someone explain how this could happen?
Sure, ground moisture exists for those who don't have insulation under the slab. However, gypsum/OSB or similar should never stand directly on the slab. Place a temporary spacer first when you screw the boards up.
An important difference is ventilation. When you lean boards against a wall (I've done that myself), you have good ventilation around the board. The inside/back of a wall is something completely different. However, I can't say if gypsum in a basement is asking for trouble.ByggaNytt said:
Minerit doesn't feel like an option. I might as well plaster the existing basement wall. I thought fiberglass gypsum was a good compromise between "easy to screw into" and moisture resistance. You can always make a little extra effort and build a ventilated wall, it's actually quite easy. With proper ventilation in the wall, it should even be "safe" to use OSB..... :
I even built an interior wall according to the above recipe in the boiler room against the outer wall. However, this has a 70 mm metal stud due to all the VP pipes etc., and has only been in "operation" for 11 months, so it needs to be evaluated further
Well, I'm convinced that the proposed construction will not mold. Ventilation is, as mentioned, the core issue here, and a 45 mm air gap should be more than sufficient. I've been involved in building a couple of "volume houses" where the "best" construction was a standing 22 nail batten directly against the Leca, then gypsum.... >
Both OSB/Gypsum are on the "warm side" of the wall, and both materials are considered to be diffusion-open.
Well, I'm convinced that the proposed construction will not mold. Ventilation is, as mentioned, the core issue here, and a 45 mm air gap should be more than sufficient. I've been involved in building a couple of "volume houses" where the "best" construction was a standing 22 nail batten directly against the Leca, then gypsum.... >
Both OSB/Gypsum are on the "warm side" of the wall, and both materials are considered to be diffusion-open.
Indeed, it can happen that any construction involving gypsum starts to mold if the environment is wrong. This also applies to wallpaper, painted fabric, and various forms of wood.ByggaNytt said:
Black mold grows at +2 to +40 degrees Celsius but thrives best at 23-37 degrees. For growth, it requires high humidity, RH >90-95%.
I don't know the exact conditions at Petra's home, so the recommendation is suspenders and a belt...
Why not plaster the entire wall?
It's not insulation we're asking for, and a well-executed plaster is just as smooth as boards. In the worst case, you might have to apply a skim coat. Then use a paper wallpaper so that moisture can migrate out if needed.
The advantage of minerit is that its alkaline composition counteracts mold growth.
It's not insulation we're asking for, and a well-executed plaster is just as smooth as boards. In the worst case, you might have to apply a skim coat. Then use a paper wallpaper so that moisture can migrate out if needed.
The advantage of minerit is that its alkaline composition counteracts mold growth.
Paper wallpaper + moisture = moldpoiu said: