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
profil65 schrieb:
Let’s get started:
Do you think ventilating after showering is enough?
Do you really believe that ventilating helps when the outside temperature is around 5-10°C (41-50°F) with 90% relative humidity? Hi, after showering I usually had about 90%. After ventilating, about 60%.
But I think I need a proper measuring device that is reliable.
One more question for the original poster (everyone else, please don’t answer in advance 🙂)
Do you think airing out the bathroom once after showering and then leaving the house is enough?
Do you believe that hanging wet towels outside after showering and quickly using a squeegee on the shower or wet surfaces helps?
Would you be willing to install a simple humidity-controlled electric bathroom fan?
Are you (or you all) able to ventilate more frequently and for longer periods?
Do you think airing out the bathroom once after showering and then leaving the house is enough?
Do you believe that hanging wet towels outside after showering and quickly using a squeegee on the shower or wet surfaces helps?
Would you be willing to install a simple humidity-controlled electric bathroom fan?
Are you (or you all) able to ventilate more frequently and for longer periods?
I was also wondering why the previous owners installed a simple (thin) interior insulation. My guess is there were reasons for that...
Tolentino schrieb:
Were there? You mean there was (even if rudimentary) interior insulation, which you have now removed?
W
WilderSueden5 Nov 2023 12:09I don’t understand the point of these leading questions. It has already been stated that manual ventilation is not sufficient with new windows. Unless you consider ventilation a hobby. And if you start using mechanical ventilation, it should not be limited to the bathroom but also cover the living areas. Ventilation alone—whether manual or automatic—will not solve the problem. Older building walls simply have poor insulation, and the dew point can only be avoided with very dry air. In the long term, external insulation needs to be installed.
X
xMisterDx5 Nov 2023 12:14Nitpicking aside, understanding the relationship between temperature, relative humidity, and absolute humidity has never seriously harmed anyone.
But the situation is basically clear, right?
A room temperature of 20°C (68°F) is simply too low; try heating up to 22-23°C (72-73°F). Of course, this means about 15-20% higher heating costs, I get that.
We had exactly the same problem in our rental apartment during the winter of 2022/23, when everyone was supposed to save gas. Previously, everywhere was kept at 23°C (73°F), then I lowered the temperature in my home office to 20°C (68°F), and after 3 weeks mold appeared on the north-facing wall. The three winters before that, at 22-23°C (72-73°F), there was no mold.
But the situation is basically clear, right?
A room temperature of 20°C (68°F) is simply too low; try heating up to 22-23°C (72-73°F). Of course, this means about 15-20% higher heating costs, I get that.
We had exactly the same problem in our rental apartment during the winter of 2022/23, when everyone was supposed to save gas. Previously, everywhere was kept at 23°C (73°F), then I lowered the temperature in my home office to 20°C (68°F), and after 3 weeks mold appeared on the north-facing wall. The three winters before that, at 22-23°C (72-73°F), there was no mold.
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