Hello everyone,
I have a question for the building experts regarding interior plaster. Unfortunately, we have not yet found a well-founded opinion on this.
In our preliminary building specification (contract not yet signed), it states that the interior walls are to be finished with gypsum plaster.
When our building plans became more concrete, I also got some literature. From the book "(K)ein Pfusch am Bau: Wie ein Bausachverständiger (s)ein Haus richtig und dennoch kostengünstig bauen würde“ by Günther Nussbaum-Sekora (which I find really good as a layperson), the following quote:
[ I]Due to my inquiry (note: building surveyor), the building quality could already be improved before the first ground-breaking.[/I]
[ I]According to the building specification “interior plaster machine application”[/I]
[ I]What was meant was the cheaper and moisture-sensitive gypsum plaster. It was upgraded at no extra cost to lime plaster. The high pH value of lime (>12) prevents microbial growth.[/I]
End of quote
In addition, we will be building with Ytong blocks and installing a ventilation system.
So now my question to you is:
Does anyone have experience with this?
Are there other aspects besides microbial growth that would speak for or against lime plaster? (e.g. problematic texture, more difficult application or finishing, paintability, wallpapering issues, moisture sensitivity, or similar)
(where I understand the purpose of lime plaster is to absorb moisture better)
If you support using lime plaster, would you use it throughout the entire living area as interior plaster or only in wet areas (bathroom, kitchen, utility room)?
If my assumption is correct that lime plaster absorbs moisture better – does this still make sense if a ventilation system is installed that already removes room humidity?
Thank you very much for your answers
f-pNo
I have a question for the building experts regarding interior plaster. Unfortunately, we have not yet found a well-founded opinion on this.
In our preliminary building specification (contract not yet signed), it states that the interior walls are to be finished with gypsum plaster.
When our building plans became more concrete, I also got some literature. From the book "(K)ein Pfusch am Bau: Wie ein Bausachverständiger (s)ein Haus richtig und dennoch kostengünstig bauen würde“ by Günther Nussbaum-Sekora (which I find really good as a layperson), the following quote:
[ I]Due to my inquiry (note: building surveyor), the building quality could already be improved before the first ground-breaking.[/I]
[ I]According to the building specification “interior plaster machine application”[/I]
[ I]What was meant was the cheaper and moisture-sensitive gypsum plaster. It was upgraded at no extra cost to lime plaster. The high pH value of lime (>12) prevents microbial growth.[/I]
End of quote
In addition, we will be building with Ytong blocks and installing a ventilation system.
So now my question to you is:
Does anyone have experience with this?
Are there other aspects besides microbial growth that would speak for or against lime plaster? (e.g. problematic texture, more difficult application or finishing, paintability, wallpapering issues, moisture sensitivity, or similar)
(where I understand the purpose of lime plaster is to absorb moisture better)
If you support using lime plaster, would you use it throughout the entire living area as interior plaster or only in wet areas (bathroom, kitchen, utility room)?
If my assumption is correct that lime plaster absorbs moisture better – does this still make sense if a ventilation system is installed that already removes room humidity?
Thank you very much for your answers
f-pNo
N
nordanney23 Nov 2015 20:38Sebastian79 schrieb:
In my opinion, gypsum on walls and even on floors no longer belongs there due to moisture-related issues. However, I wouldn’t want to impose my opinion on anyone...What kind of moisture issues?I’m curious – so far, I have never encountered any plaster other than gypsum. It is used in nearly 100% of houses here.
Amidst all the personal opinions, it should not be overlooked that the chosen plaster must be matched to the respective substrate according to the relevant DIN standards and recognized rules of technology (a.a.R.d.T). The plaster base and its pretreatment play a crucial role in selecting the plaster category, and manufacturers of the stone types used provide recommendations that must be strictly followed. The composition and application of plaster mortars are further regulated by DIN V 18550 and DIN EN 13279.
One basic rule, for example, is that the plaster must never be harder than the substrate to accommodate thermal and structural stresses. A lime-cement or cement plaster is relatively dense and increasingly capillary non-absorbent, making it unsuitable for very soft aerated concrete. For interior plaster, a hydraulic lime plaster (MG P Ic), a gypsum-lime plaster (MG P IVc), or a lime-gypsum plaster (MG P IVd) is therefore appropriate.
Gypsum must not come into contact with fresh, unset concrete or cement-containing mortar because the dissolved CaSO4 in cement can trigger the so-called “sulfate attack” through the formation of the mineral salt ettringite, among others. This salt causes severe plaster damage due to its volume expansion.
Decisions for or against certain building materials or component assemblies should therefore not be based solely on personal preferences, random availability at the building supply store, or the profit motives of the construction company, but on the structural and building physics requirements.
One basic rule, for example, is that the plaster must never be harder than the substrate to accommodate thermal and structural stresses. A lime-cement or cement plaster is relatively dense and increasingly capillary non-absorbent, making it unsuitable for very soft aerated concrete. For interior plaster, a hydraulic lime plaster (MG P Ic), a gypsum-lime plaster (MG P IVc), or a lime-gypsum plaster (MG P IVd) is therefore appropriate.
Gypsum must not come into contact with fresh, unset concrete or cement-containing mortar because the dissolved CaSO4 in cement can trigger the so-called “sulfate attack” through the formation of the mineral salt ettringite, among others. This salt causes severe plaster damage due to its volume expansion.
Decisions for or against certain building materials or component assemblies should therefore not be based solely on personal preferences, random availability at the building supply store, or the profit motives of the construction company, but on the structural and building physics requirements.
So what are the pros and cons of gypsum plaster, lime plaster, lime-cement plaster, and lime-gypsum plaster in living spaces? I have reviewed various construction specifications, and they always list gypsum plaster. Also, almost all prefabricated houses use gypsum drywall panels as the innermost layer.
It is cheaper there. It might also be something regional?
Lime-cement plaster is probably harder to get smooth but it is tougher (?), lime-cement plaster is alkaline and helps prevent mold caused by poor construction – it can absorb more vapor-permeable silicate paint.
I think people are happy with both, and most don’t know or notice the difference.
Lime-cement plaster is probably harder to get smooth but it is tougher (?), lime-cement plaster is alkaline and helps prevent mold caused by poor construction – it can absorb more vapor-permeable silicate paint.
I think people are happy with both, and most don’t know or notice the difference.
S
Sebastian7927 Nov 2015 19:46It is simply the most cost-effective option and quickly provides visually clean walls – this is what most homeowners prefer.
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