Hello everyone,
I urgently need some advice.
We have a house that we bought in 2019 and partially renovated. All the windows are new with double glazing, and we installed underfloor heating.
In recent years, we have already experienced high indoor humidity levels, up to about 65% in winter.
This year, we even had high humidity of 55-65% in all rooms during the summer, and ventilating did not help. Now, in autumn, the humidity is rising above 70%, and we are gradually becoming unsure of what to do.
I measured the walls in all rooms with a moisture meter. The north-facing wall shows about 16% moisture in the corners. The interior walls have about 12%. However, there are no walls that are visibly wet. The roof and walls are also tight.
We regularly air the rooms by cross-ventilation, morning and evening, and now have a dehumidifier running in the bedroom. Still, mold is beginning to grow.
The north basement wall is also damp, but there is roofing felt between the stones, so I don’t think the moisture is rising from below.
Additionally, last year I insulated the basement corner with EPS insulation boards.
I believe I have covered all relevant details.
Does anyone have any idea what I might be doing wrong or where I should look next?
Best regards,
andre007
I urgently need some advice.
We have a house that we bought in 2019 and partially renovated. All the windows are new with double glazing, and we installed underfloor heating.
In recent years, we have already experienced high indoor humidity levels, up to about 65% in winter.
This year, we even had high humidity of 55-65% in all rooms during the summer, and ventilating did not help. Now, in autumn, the humidity is rising above 70%, and we are gradually becoming unsure of what to do.
I measured the walls in all rooms with a moisture meter. The north-facing wall shows about 16% moisture in the corners. The interior walls have about 12%. However, there are no walls that are visibly wet. The roof and walls are also tight.
We regularly air the rooms by cross-ventilation, morning and evening, and now have a dehumidifier running in the bedroom. Still, mold is beginning to grow.
The north basement wall is also damp, but there is roofing felt between the stones, so I don’t think the moisture is rising from below.
Additionally, last year I insulated the basement corner with EPS insulation boards.
I believe I have covered all relevant details.
Does anyone have any idea what I might be doing wrong or where I should look next?
Best regards,
andre007
When was the first occupancy?
Is this a detached single-family house, or what type of building is it?
Note regarding humidity levels: Relative humidity always depends on indoor temperature and outdoor weather conditions (temperature/humidity/season/etc.). This means that in summer, with windows frequently open, indoor humidity simply reflects the outdoor conditions — normal values can range from 30% up to over 90%, depending on the weather, and this is not problematic.
In winter, heating and ventilation habits as well as user behavior play a significant role.
There is often surprisingly incorrect user behavior with underfloor heating systems, especially when there is little experience with them.
Regarding ventilation, the question is whether one can or is willing to ventilate often enough. For example, if no one is home during the day and wet towels or a damp shower release moisture gradually into the indoor air, walls, and furniture, even after what seems like sufficient morning ventilation, moisture can accumulate throughout the day.
Is this a detached single-family house, or what type of building is it?
Note regarding humidity levels: Relative humidity always depends on indoor temperature and outdoor weather conditions (temperature/humidity/season/etc.). This means that in summer, with windows frequently open, indoor humidity simply reflects the outdoor conditions — normal values can range from 30% up to over 90%, depending on the weather, and this is not problematic.
In winter, heating and ventilation habits as well as user behavior play a significant role.
There is often surprisingly incorrect user behavior with underfloor heating systems, especially when there is little experience with them.
Regarding ventilation, the question is whether one can or is willing to ventilate often enough. For example, if no one is home during the day and wet towels or a damp shower release moisture gradually into the indoor air, walls, and furniture, even after what seems like sufficient morning ventilation, moisture can accumulate throughout the day.
Tolentino schrieb:
Weren't there? You mean there was (albeit rudimentary) internal insulation that you have now removed?Exactly, there was internal insulation. But isn’t such internal insulation even worse in my case? I was bothered by not being able to see what was underneath. As an alternative, I was considering climate boards and wanted to test them in the bedroom.profil65 schrieb:
When was the house first occupied?
Is it a detached single-family house or something else?
Note on humidity levels: Relative humidity always depends on room temperature and outdoor weather conditions (temperature/humidity/season/…). That means in summer, with windows frequently open, indoor humidity simply reflects the external conditions = normal = ranging from 30% to over 90% depending on the weather, all unproblematic = normal.
In winter, heating and ventilation habits as well as user behavior are very important.
With underfloor heating, incorrect user behavior is surprisingly common, especially without prior experience.
Regarding ventilation behavior, the question is whether I can/want to ventilate often enough, or if no one is home during the day and wet towels or a damp shower slowly release moisture throughout the day into the room air, walls, and furniture, despite having ventilated thoroughly in the morning (which may only seem sufficient). We moved in in 2019.
It is a detached single-family house.
Actually, in our area this year, the humidity levels have been generally very high. Currently between 70 and 90%.
We try to ventilate regularly by briefly opening windows. After showering, we open the windows fully until the humidity drops to 60%. We now have a measuring device in every room.
andre007 schrieb:
We moved in in 2019.
It is a detached single-family house.
Actually, in our area this year, there has generally been very high humidity. Currently between 70 and 90%.
We try to ventilate regularly by fully opening windows after showering until the humidity drops to 60%. We now have a measuring device in every room. Now, let’s jump in:
Do you think ventilating after showering is enough?
Do you think ventilating is effective when the outside temperature is about 5–10°C (41–50°F) with 90% relative humidity?
W
WilderSueden5 Nov 2023 11:28profil65 schrieb:
Do you think ventilation helps when it’s about 5–10°C (41–50°F) outside with 90% relative humidity?What’s the point of the question? 100% humidity at 10°C (50°F) corresponds to about 55% at 20°C (68°F). So ventilating after a shower definitely helps a lot. There’s no harm in doing it otherwise either. Of course, you can’t expect miracles in autumn weather.WilderSueden schrieb:
What’s the point of the question? 100% humidity at 10 degrees Celsius (50°F) corresponds to about 55% at 20 degrees Celsius (68°F). So it makes quite a difference after showering. And otherwise, there’s nothing wrong with it. Of course, you can’t expect miracles in autumn weather. Actually, I was hoping to get exactly that answer from the original poster... you are right, of course... but no prompting allowed 😉
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