ᐅ Which wall assembly is suitable for being vapor-permeable?
Created on: 15 Mar 2021 12:34
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Hausbauer2021
Hello everyone,
I am currently researching wall construction with a focus on vapor-open systems. I am very concerned about mold growth in the house, which is why I have often read that a vapor-open build is preferable (using a vapor retarder instead of a vapor barrier). However, when I look at the wall constructions of various manufacturers, a vapor barrier is often installed rather than a retarder (for example, Danwood). If the mechanical ventilation system fails, does this then inevitably lead to mold growth? Can anyone share their experience with how this (PE foil) actually performs in a house? Are there wall constructions where a mechanical ventilation system is installed as a nice-to-have but not essential? We currently live in an apartment and have to air the rooms multiple times in winter to prevent mold from forming under the blinds’ boxes. Are there houses or walls that do not experience these problems? We definitely want a ventilation system, but I would like to avoid the worry of mold growth within a few days if the system fails.
Thank you very much for your experiences.
I am currently researching wall construction with a focus on vapor-open systems. I am very concerned about mold growth in the house, which is why I have often read that a vapor-open build is preferable (using a vapor retarder instead of a vapor barrier). However, when I look at the wall constructions of various manufacturers, a vapor barrier is often installed rather than a retarder (for example, Danwood). If the mechanical ventilation system fails, does this then inevitably lead to mold growth? Can anyone share their experience with how this (PE foil) actually performs in a house? Are there wall constructions where a mechanical ventilation system is installed as a nice-to-have but not essential? We currently live in an apartment and have to air the rooms multiple times in winter to prevent mold from forming under the blinds’ boxes. Are there houses or walls that do not experience these problems? We definitely want a ventilation system, but I would like to avoid the worry of mold growth within a few days if the system fails.
Thank you very much for your experiences.
ypg schrieb:
And yes: new houses are practically airtight. But they stay nice and warm.YES, especially in midsummer 😀Mold can develop even in a ventilated room.
Mold occurs where there is constant moisture. This happens when warm, humid air condenses in a joint, corner, angle, or recess due to thermal insulation defects that cause cooler spots. These areas dry poorly, and suddenly the unwanted growth appears. I prefer monolithic walls for this reason because insulation errors cannot happen there; the thick Ytong block itself acts as insulation, and it is evenly built throughout. Inside the wall, there is no plastic vapor barrier. A cement and aerated concrete wall absorbs moisture and releases it again, as long as you don’t block it with vapor-retarding wall coverings on the inside. Ventilation is still necessary, but our window rebate profiles are sufficient. After returning from vacation, there is no need to worry about finding mold despite all the windows being closed for two weeks.
Mold occurs where there is constant moisture. This happens when warm, humid air condenses in a joint, corner, angle, or recess due to thermal insulation defects that cause cooler spots. These areas dry poorly, and suddenly the unwanted growth appears. I prefer monolithic walls for this reason because insulation errors cannot happen there; the thick Ytong block itself acts as insulation, and it is evenly built throughout. Inside the wall, there is no plastic vapor barrier. A cement and aerated concrete wall absorbs moisture and releases it again, as long as you don’t block it with vapor-retarding wall coverings on the inside. Ventilation is still necessary, but our window rebate profiles are sufficient. After returning from vacation, there is no need to worry about finding mold despite all the windows being closed for two weeks.
Nordlys schrieb:
Ventilation is still necessary, but our window rebate vents are sufficient,= uncontrolled residential ventilation Ventilating is essential to prevent any issues. This is the only aspect the original poster must keep in mind to feel confident.
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Hausbauer202116 Mar 2021 07:42Good morning,
Yesterday, I did some research on window rebate ventilation systems and I am wondering why these are rarely, if ever, offered in new buildings. I find the system very effective and it doesn’t require a central ventilation unit. Or does this system only work with certain building constructions?
Yesterday, I did some research on window rebate ventilation systems and I am wondering why these are rarely, if ever, offered in new buildings. I find the system very effective and it doesn’t require a central ventilation unit. Or does this system only work with certain building constructions?
Hausbauer2021 schrieb:
I did some research yesterday on window rebate vents and I’m wondering why these are hardly ever offered in new builds?... because they are basically a small alternative to permanently tilted windows. They continuously let warm air escape outside and cold air enter the house. Without any control or heat recovery. This is also not favorable for energy efficiency calculations like those for KfW.However, it is still an acceptable solution to ensure a constant supply of fresh air inside the house. Even though it seems odd to build an airtight house only to then have effectively uncontrolled openings in the facade.
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Myrna_Loy16 Mar 2021 08:57nordanney schrieb:
= uncontrolled residential ventilation
Ventilation is essential to prevent problems. This is the only point the original poster needs to keep in mind to feel confident. I would add: proper ventilation is crucial.
As someone with allergies, I prefer manual ventilation through windows – mechanical ventilation systems should be cleaned regularly, which is often overlooked.
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