Hi,
I need some advice. In our house (3 years old, solid construction, 36.5cm (14 inches) Poroton blocks), there is mold forming in one room at the corner where two walls (both exterior walls) and the ceiling (upper floor under the flat roof) meet. There is no mold anywhere else in the house, and we ventilate the room daily.
I had the roofer check the site, and they removed the roof down to the concrete layer, but everything is dry there.
Now we’re really stuck... Everyone is puzzled. What could be causing this problem?
Thank you and best regards
I need some advice. In our house (3 years old, solid construction, 36.5cm (14 inches) Poroton blocks), there is mold forming in one room at the corner where two walls (both exterior walls) and the ceiling (upper floor under the flat roof) meet. There is no mold anywhere else in the house, and we ventilate the room daily.
I had the roofer check the site, and they removed the roof down to the concrete layer, but everything is dry there.
Now we’re really stuck... Everyone is puzzled. What could be causing this problem?
Thank you and best regards
Bookstar schrieb:
Yes, but who heats a bedroom above 19 degrees? Often, it is much cooler there. I don’t see this as a practical solution!Exactly, and that’s precisely why you need a mechanical (central or decentralized) ventilation system with heat recovery. Once again, QED: a new build requires a ventilation system.
fragg schrieb:
Well, that’s exactly why you need a mechanical (central or decentralized) ventilation system with heat recovery. Once again, QED: new buildings require a ventilation system. I don’t agree with that as a general statement. Thermal bridges can be avoided and, in my opinion, they are less common in new buildings than they used to be, back when balconies were simply cast onto the structure without insulation!
What should cause thermal bridges in simple floor plans with very good insulation? In addition, airtightness has a positive effect when ensured, as no convection can occur and therefore no moisture accumulation happens at critical building components.
Well over 50% of new buildings in my construction area still do not have a ventilation concept today, contrary to the requirements of the energy saving regulations. And yet, these people generally do not have problems with mold.
Wow, I’m really glad that I can sleep mold-free in a drafty old building at 17°C (63°F). That just can’t be right...
P.S. Thermal bridge or not: with the given values (19°C (66°F) air temperature, 68% humidity), the dew point is only at 13°C (55°F). So there shouldn’t be any condensation in a spot that’s 17°C (63°F) warm. Could there still be a leak somewhere or maybe residual construction moisture?
P.S. Thermal bridge or not: with the given values (19°C (66°F) air temperature, 68% humidity), the dew point is only at 13°C (55°F). So there shouldn’t be any condensation in a spot that’s 17°C (63°F) warm. Could there still be a leak somewhere or maybe residual construction moisture?
Hello
A quick tip to at least temporarily counteract the effects:
buy a small fan. 5-6 watts is more than enough. Position it about 20-30cm (8-12 inches) from the mold-affected area and let it run. You will see that within a day or two, the wall will be dry (at least on the surface).
At the same time, start investigating the causes.
Steven
A quick tip to at least temporarily counteract the effects:
buy a small fan. 5-6 watts is more than enough. Position it about 20-30cm (8-12 inches) from the mold-affected area and let it run. You will see that within a day or two, the wall will be dry (at least on the surface).
At the same time, start investigating the causes.
Steven
P
Pluto197721 Nov 2019 11:12Hi,
thanks for all the tips. I’m constantly learning here and realize that, like with many things in construction, I was inadequately informed or misinformed... (Next time with the next house, I’ll do it right).
I definitely need to adjust the ventilation behavior. I already ordered a dehumidifier yesterday and, of course, something to counteract the mold in the short term. I will also try the fan right away.
I’ve already looked at some websites about decentralized ventilation systems.
What needs to be clarified now is whether this is a construction defect or just an unfortunate corner. Although I wonder if that will help me at all—because rebuilding that corner won’t really be an option.
Thanks a lot and best regards
thanks for all the tips. I’m constantly learning here and realize that, like with many things in construction, I was inadequately informed or misinformed... (Next time with the next house, I’ll do it right).
I definitely need to adjust the ventilation behavior. I already ordered a dehumidifier yesterday and, of course, something to counteract the mold in the short term. I will also try the fan right away.
I’ve already looked at some websites about decentralized ventilation systems.
What needs to be clarified now is whether this is a construction defect or just an unfortunate corner. Although I wonder if that will help me at all—because rebuilding that corner won’t really be an option.
Thanks a lot and best regards
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