Hello,
Over the turn of the year 2016/17, our L-shaped bungalow was built using sand-lime brick construction. External wall insulation (EWI) was applied, I believe, in November 2016. Inside, gypsum plaster was used, with underfloor heating installed beneath a cement screed. During the last four weeks before moving in (in January 2017), two dehumidifiers were used. The drying progress was said to be good enough that the floor moisture measurement gave the green light for our glued vinyl flooring. We moved in mid-February 2017.
Yesterday, the inspector came. Not without reason. There are condensation issues on an exterior wall in the bedroom and in the utility room. On average, the house has an absolute humidity of 9.5–11.5 g/kg of air. Our inexpensive hygrometers distributed throughout the house showed mostly 55–60% relative humidity in March but have risen noticeably since mid-April, reaching up to 75% in the bedroom. His measurements indicated that this is very likely due to residual construction moisture (the report is still pending). This could also explain why our vinyl flooring has started to lift again *grumble*.
In short: it’s my house, and I want to avoid further problems as quickly as possible. At the moment, I don’t care who is at fault here (whether we should have moved in later or ventilated better… that’s not the point here). So far, we have only aired the house by opening windows for cross-ventilation once a day. I’m not sure yet if twice a day is feasible. That’s why I considered setting up another dehumidifier now in addition to ventilating. Whether it helps, I’ll only find out afterwards. My question is: is it better to use two smaller units (each 10–15 L/day) or one larger one (50 L/day)? It’s also a matter of cost. The smaller ones have the advantage that I can place them distributed around the house but have only a very small condensate tank and have to hope the automatic shutoff works properly. For the large one, I found a model with an integrated condensate pump – it could run continuously. But I suppose proper air circulation in the house would be missing then, right? Does anyone have advice on which option I should choose?
Best regards
PS: I’m not sure about the category placement here in the forum, so please feel free to move this if needed. Thanks
Over the turn of the year 2016/17, our L-shaped bungalow was built using sand-lime brick construction. External wall insulation (EWI) was applied, I believe, in November 2016. Inside, gypsum plaster was used, with underfloor heating installed beneath a cement screed. During the last four weeks before moving in (in January 2017), two dehumidifiers were used. The drying progress was said to be good enough that the floor moisture measurement gave the green light for our glued vinyl flooring. We moved in mid-February 2017.
Yesterday, the inspector came. Not without reason. There are condensation issues on an exterior wall in the bedroom and in the utility room. On average, the house has an absolute humidity of 9.5–11.5 g/kg of air. Our inexpensive hygrometers distributed throughout the house showed mostly 55–60% relative humidity in March but have risen noticeably since mid-April, reaching up to 75% in the bedroom. His measurements indicated that this is very likely due to residual construction moisture (the report is still pending). This could also explain why our vinyl flooring has started to lift again *grumble*.
In short: it’s my house, and I want to avoid further problems as quickly as possible. At the moment, I don’t care who is at fault here (whether we should have moved in later or ventilated better… that’s not the point here). So far, we have only aired the house by opening windows for cross-ventilation once a day. I’m not sure yet if twice a day is feasible. That’s why I considered setting up another dehumidifier now in addition to ventilating. Whether it helps, I’ll only find out afterwards. My question is: is it better to use two smaller units (each 10–15 L/day) or one larger one (50 L/day)? It’s also a matter of cost. The smaller ones have the advantage that I can place them distributed around the house but have only a very small condensate tank and have to hope the automatic shutoff works properly. For the large one, I found a model with an integrated condensate pump – it could run continuously. But I suppose proper air circulation in the house would be missing then, right? Does anyone have advice on which option I should choose?
Best regards
PS: I’m not sure about the category placement here in the forum, so please feel free to move this if needed. Thanks
K
Knallkörper5 May 2017 23:40In our case, a single airing in the morning is sufficient for the bedrooms. We deliberately chose not to install a mechanical ventilation system. The relative humidity ranges between 38 and 45%. We have been living in the new building for 2 weeks now. Overnight, the humidity in the bedroom rises by a maximum of 5 percentage points. It should be noted that the smallest bedroom is 20 m2 (215 sq ft) with high ceilings. During the construction phase, we used dehumidifiers for several weeks to remove moisture; by the way, we simply attached garden hoses to the devices, which works with most models. In my opinion, technical drying before moving in is absolutely necessary when the house is built "quickly."
Knallkörper schrieb:
For us, ventilating the bedrooms once in the morning is sufficient. We deliberately chose not to install a mechanical ventilation system. The relative humidity stays between 38 and 45%. We have been living in the new build for two weeks. Overnight, the humidity in the bedroom increases by at most 5 percentage points. It should be noted that the smallest bedroom is 20 m2 (215 sq ft) with high ceilings. During construction, we used dehumidifiers for many weeks to remove moisture; Mechanical ventilation or not… when it comes to damp walls, something needs to be done before moving in – without mechanical ventilation after moving in, you need to pay close attention to your house: what does it need, what level of ventilation is sufficient. If the shell of the building became very damp, once the plaster is applied and the screed is in, you have to take action!Similar topics