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
Nida35a schrieb:
Then only blown-in insulation and increasing the room temperature to 22-23 degrees, and keeping furniture away from the exterior walls remain. Exactly, keep the temperature in the affected rooms consistently high AND doors closed, track humidity, and open windows briefly if needed until humidity drops. Also, no plants in the affected rooms.
It’s helpful to always know the outside temperature and humidity to see if airing out is actually beneficial. There are charts online showing temperature alongside absolute and relative humidity.
What’s crucial is that the north-facing wall warms up enough to prevent condensation.
In the long term, only proper insulation will help. This also saves heating oil and ensures a comfortable indoor environment.
I’m not familiar with blown-in insulation myself; we have exterior insulation with mineral wool.
There are usually subsidies available for insulation.
andre007 schrieb:
The stains are all on the north-facing wall and in the corners. These rooms are the living room, office, and bedroom.
The heating is on continuously (except in summer). We have set the room temperature to 20°C (68°F).
The doors are almost always open. This is typical; north-facing walls are the coldest, as are the corners. 20°C (68°F) is not enough in an uninsulated older building (but it is sufficient if insulated).
Doors should be kept closed because otherwise the humidity spreads throughout and condenses on the coldest wall. The key factors are always the balance between temperature, relative humidity, and the temperature of the coldest building element in the affected room.
You can adjust these variables. And when the doors are closed, it’s easier since you only need to “monitor” one room.
W
WilderSueden5 Nov 2023 09:10Tigerlily schrieb:
It’s also helpful to always know the outside temperature and humidity so you can tell if airing out the room will actually be effective.In this regard, you basically can’t go wrong. Mold doesn’t just need moisture, it also requires a wall surface to drop below the dew point. If it’s cold enough for that, the outside air is usually cold enough that, even at 100% humidity, the building will tend to dry out rather than absorb moisture.Questions:
How was the house heated in the past? (e.g., central heating with radiators under the windows, stove heating, etc.)
Did it have double-glazed windows with seals?
Was the building free of mold in the past, or were there already moisture/mold problems before the renovation?
How was the house heated in the past? (e.g., central heating with radiators under the windows, stove heating, etc.)
Did it have double-glazed windows with seals?
Was the building free of mold in the past, or were there already moisture/mold problems before the renovation?
profil65 schrieb:
Questions:
How was the house heated before? (e.g., central heating with radiators under the windows, stove heating, etc.?)
Did it have double-glazed windows with seals?
Was the building free of mold in the past, or were there moisture/mold problems before the renovation?The heating system is the same, but instead of underfloor heating, radiators were used. We closed off the radiator niches. The windows were also double-glazed with seals, but much older. I think the key issue was that the roller shutter boxes above the windows were not insulated. Air could circulate there. We did not see any mold. On the north wall in the living room, there was glass fiber wallpaper, and in the bedroom, wood paneling with about 3 cm (1¼ inches) of polystyrene insulation underneath. The ceilings were also covered with wood and polystyrene. I laid 10 cm (4 inches) of polystyrene on the floor of the upper floor.
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