ᐅ Humidity 60% - Masonry damp

Hello, we are now experiencing our first winter in the house.
The humidity level is always around 60%, sometimes even higher.
The exterior plaster was completed last week.
Moisture also accumulates on the roof windows.

Could it be that the masonry is still damp?
It’s a brick house without mechanical ventilation.

Regards, Patrick

Do you really need to be told to air out the place several times a day to prevent mold from developing in your brand-new house? Or can you figure that out on your own? A 60% humidity level is too high given the current outdoor air moisture and indicates insufficient ventilation.

Hmm, well, other than opening the windows every day, I can't really do much more.

And with 80% outdoor humidity, it doesn’t really decrease either.

I guess I should have mentioned that this is despite ventilating… sorry, my mistake.

Ventilate or risk mold—your choice. You were able to build a house, so managing adequate ventilation should be no problem.

Also, educate yourself about the absolute water vapor content of air at low temperatures. Or get a dew point calculator app.

For comparison: Here is the first winter in a solidly built new home, which has a LOT of residual moisture due to the short construction period. Today, I lowered the ventilation setting by one level to prevent the indoor humidity from dropping below 40%. The outside air is quite dry at the moment.

Ötzi Ötztaler schrieb:

The outside air is quite dry at the moment.

That’s not correct, iOS shows 83% and Netatmo currently reads 80%, so it’s definitely not quite dry! The original poster also mentions 80%.

But in terms of appearance, Ötzi is right!

Zaba12 schrieb:

That’s not correct, iOS shows 83% and Netatmo currently reads 80%, so it’s not properly dry! The original poster also mentions 80%.

Actually, it is correct! It relates to the vapor pressure curve of water in air.

Right now, the outside temperature here is 2.9°C (37.2°F) with 82% relative humidity. That corresponds to a dew point of 0.2°C (32.4°F) or an absolute water vapor content of 4.9g/m3.

If you warm this outside air to a room temperature of 22°C (71.6°F) while keeping the water vapor content constant, the indoor relative humidity will be only about 25% (!!)

That’s why building drying in winter works much better than in summer, provided that there is sufficient ventilation and proper heating. The original poster is not ventilating enough and may soon be surprised by the consequences.