ᐅ Which type of plaster should be used? What are the differences?
Created on: 9 Jan 2020 13:53
T
Tx-25
Hello.
Soon the plasterers will arrive at our new build.
Since we want to have only a small amount of wallpaper and tiles on the walls, we have now chosen gypsum plaster from the options offered by our builder (cement plaster and gypsum plaster). Due to its smoother surface, it should be better suited for our project. According to the builder, the entire house can only be treated with one type of plaster. So it is not possible to switch to cement plaster in the bathrooms.
My question is:
Is gypsum plaster always the same as lime gypsum plaster? If not, what are the differences between lime gypsum plaster and gypsum plaster? Is the only difference the mold-inhibiting effect of lime?
Additionally, it is important to us that no moisture can penetrate through the plaster. Is this true for all types of plaster? Cement plaster absorbs moisture to some extent and releases it again. Wouldn’t that mean that moisture also passes through the plaster? This concerns the stone wool insulation behind the plaster. In some areas, moisture protection is only ensured by the combination of plaster and vapor barrier. Or would you recommend a completely different plaster? What do you think about using gypsum plaster in the bathroom? A controlled ventilation system with heat recovery is in place.
Soon the plasterers will arrive at our new build.
Since we want to have only a small amount of wallpaper and tiles on the walls, we have now chosen gypsum plaster from the options offered by our builder (cement plaster and gypsum plaster). Due to its smoother surface, it should be better suited for our project. According to the builder, the entire house can only be treated with one type of plaster. So it is not possible to switch to cement plaster in the bathrooms.
My question is:
Is gypsum plaster always the same as lime gypsum plaster? If not, what are the differences between lime gypsum plaster and gypsum plaster? Is the only difference the mold-inhibiting effect of lime?
Additionally, it is important to us that no moisture can penetrate through the plaster. Is this true for all types of plaster? Cement plaster absorbs moisture to some extent and releases it again. Wouldn’t that mean that moisture also passes through the plaster? This concerns the stone wool insulation behind the plaster. In some areas, moisture protection is only ensured by the combination of plaster and vapor barrier. Or would you recommend a completely different plaster? What do you think about using gypsum plaster in the bathroom? A controlled ventilation system with heat recovery is in place.
Tx-25 schrieb:
Some cables and empty conduits, for example, run over the knee wall to the vapor barrier. The transition there always had to be notched. Huh? Do you have a photo? That sounds quite unusual.
Some of this is not very clear.
If the electrician has gone through the vapor barrier membrane, they need to properly reseal it. The same applies if the membrane has been damaged.
Where the membrane meets the wall, it is often embedded in plaster. You can plaster over it again there. However, applying plaster over the membrane with insulation behind it is usually only necessary in rare cases. In such cases, a plaster base or carrier would be required. I can only imagine this being done in small areas. If you have photos, you should share them, but as it stands, it’s difficult to understand.
The plaster should never be sealed. The membrane must be airtight, or the plaster is sufficient if the joint is embedded in plaster.
Much has already been said correctly about plastering.
There are also gypsum plasters with lime content, which are even more cost-effective in terms of material than pure gypsum plaster. So you need to know exactly which types of plaster have been offered.
If the electrician has gone through the vapor barrier membrane, they need to properly reseal it. The same applies if the membrane has been damaged.
Where the membrane meets the wall, it is often embedded in plaster. You can plaster over it again there. However, applying plaster over the membrane with insulation behind it is usually only necessary in rare cases. In such cases, a plaster base or carrier would be required. I can only imagine this being done in small areas. If you have photos, you should share them, but as it stands, it’s difficult to understand.
The plaster should never be sealed. The membrane must be airtight, or the plaster is sufficient if the joint is embedded in plaster.
Much has already been said correctly about plastering.
There are also gypsum plasters with lime content, which are even more cost-effective in terms of material than pure gypsum plaster. So you need to know exactly which types of plaster have been offered.
F
fach1werk14 Jan 2020 08:40I would recommend keeping the plaster and its topcoat consistent in their properties. Lime is mineral-based, while gypsum is not. For lime-containing materials, I would use lime paint or the already mentioned silicate paint.
In our bathroom and sauna anteroom, the surface is lime-based. We only have automatic ventilation in the bedroom, and after 3 years we still have measuring devices installed. The lime absorbs moisture very well, as expected. However, it releases it slowly. This means that when we thoroughly wet the rooms, we need to ventilate them twice, not once. The rooms remain free of mold.
Best regards
Gabriele
In our bathroom and sauna anteroom, the surface is lime-based. We only have automatic ventilation in the bedroom, and after 3 years we still have measuring devices installed. The lime absorbs moisture very well, as expected. However, it releases it slowly. This means that when we thoroughly wet the rooms, we need to ventilate them twice, not once. The rooms remain free of mold.
Best regards
Gabriele
The topic is a bit older, but I didn’t find anything more suitable during my search, and I don’t think a new thread is necessary.
We would like to plaster some interior walls ourselves using clay plaster. The interior walls from the house providers still under consideration for us are finished with drywall panels (gypsum boards), which are usually filled, plastered, and painted by them.
Does anyone have experience with clay plaster on drywall panels? Does the clay plaster still “work” properly in that case?
@hampshire how did you handle this?
We would like to plaster some interior walls ourselves using clay plaster. The interior walls from the house providers still under consideration for us are finished with drywall panels (gypsum boards), which are usually filled, plastered, and painted by them.
Does anyone have experience with clay plaster on drywall panels? Does the clay plaster still “work” properly in that case?
@hampshire how did you handle this?
H
hampshire22 Apr 2021 23:04We had this done by the painter Stranzenbach from Wiehl. The substrate is Fermacell, which they skim-coated and prepared, then finished the surface with Lesando clay plaster mixed with straw for the visual effect. I’m not exactly sure about the specific steps involved, but I had complete trust in the cheerful team, including the master craftsman, journeyman, and assistant. We have experienced the promised properties of the clay plaster; we feel very comfortable and have never felt the air was too dry or “used up” at any time. I find the house has a pleasant smell, although I wouldn’t attribute this solely to the clay plaster, but rather to the overall choice of materials.
Great, thank you very much for your reply! That’s exactly what I wanted to hear.
We will also be using Fermacell here, so that definitely works. We’ll probably find out if a specific primer or something similar is needed ☺️
The general contractors only apply clay plaster for us with a huge extra charge, so we are now planning to do selected walls ourselves and then finish them with clay.
We will also be using Fermacell here, so that definitely works. We’ll probably find out if a specific primer or something similar is needed ☺️
The general contractors only apply clay plaster for us with a huge extra charge, so we are now planning to do selected walls ourselves and then finish them with clay.
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