I'm considering how I can dress a basement wall made of Lekablock in the simplest and best way.
I'm considering two options;
1. Steel studs against the Lekablock and installing OSB boards as well as plasterboard + wallpaper.
I'm not planning to insulate on the inside but leave a small air gap.
Also a small air gap/slit by the floor and ceiling trim. Is that necessary?
Does it pose a risk to put an OSB board there?
2. To plaster the Lekablock and paint with silicate paint.
Option 1 seems simpler, but I'm unsure if there are any associated risks.
The space of about 10 sqm is going to be a guest room where two of the sides are external walls (2.5x4 m).
I have ventilation with both supply and exhaust air. I will also install water-based underfloor heating.
Any tips?
I'm considering two options;
1. Steel studs against the Lekablock and installing OSB boards as well as plasterboard + wallpaper.
I'm not planning to insulate on the inside but leave a small air gap.
Also a small air gap/slit by the floor and ceiling trim. Is that necessary?
Does it pose a risk to put an OSB board there?
2. To plaster the Lekablock and paint with silicate paint.
Option 1 seems simpler, but I'm unsure if there are any associated risks.
The space of about 10 sqm is going to be a guest room where two of the sides are external walls (2.5x4 m).
I have ventilation with both supply and exhaust air. I will also install water-based underfloor heating.
Any tips?
It's not really idiocy, but it is an unnecessary risk to use gypsum board if you think plaster works. Gypsum plaster is a little easier for amateurs to work with, but it is also softer and more sensitive to impacts.
Plaster mesh is not needed with gypsum plaster on LECA blocks, however, you might want plaster strips to plaster against for straightness. You can use plaster mesh if you are going to plaster over cavities. You don't even need to close up a door opening; you can mesh it, frame it, and plaster directly on the mesh. 20kg gypsum plaster costs 99kr at Bauhaus the last time I was there, I think it's 0.8-0.9kg/mm/sqm; keep in mind that you should apply it in fairly thick layers to level out a crooked wall, for example. Gypsum plaster should be applied in one layer. After it has dried for about 30 minutes, it should be sponged with a float to smooth it out, then polished with a trowel or spatula. It can become as smooth as a baby's bottom if you put effort into this stage. It’s a good idea to practice on a hidden area first. There are various ways to do it depending on the desired end result. However, as I mentioned, the result is a softer surface compared to traditional plaster. Corners should be reinforced with corner profiles. Gypsum plaster also has other good properties; it balances humidity levels very well. It's virtually impossible to sand gypsum plaster as it just clogs the sandpaper, but you can go over the surface with a steel spatula multiple times, the result will be like sandpaper; if you do this before it has completely hardened, it's quite effective. If you need to fill between different materials, you’ll need reinforcement fabric, etc. Gypsum plaster adheres to many surfaces but if you have a special surface that you want it to adhere to, you might need very expensive primer. LECA blocks, plasterboard, and old plaster are not a problem though.
Thank you so much for the engagement! Incredibly valuable. I have probably decided to plaster, but not with gypsum, instead with plaster mix C (without plaster net) with plaster strips (6 mm) to achieve a somewhat even surface. Any thoughts on that?