Next step is to get an expert to assess the situation, arghhhhh
Its a fairly new construction (2011), we have all the windows open and have deployed a dehumidifier, but still the cellar does not want to become dry. There is no obvious water coming in, its simply damp...this became especially obvious with the recent hot weather. Even the stairs from the cellar (smoothed concrete) got dark spots since 2 days.
Very strange.
Often the dampness in warm air condenses on cold concrete walls to create moisture.
At the moment, Swiss Meteo is showing 84% air humidity, for your area. Although you should air the cellar, maybe not for too long. Also try to create a through draught, by using a fan positioned between two open windows.
Unless your dehumidifier is running constantly, you may want to look for a something I bought from Landi for 7,00 - an oval plastic bowl, with an internal tray and slatted lid. On the inside tray is placed a bag of water absorbing granules, which then drips the water in the bowl underneath.
A few of these placed around the cellar may help.
Ours was humid and water would run in so much that we needed a waterpump in there. We turned that on about 4 times a week.
Tha basement in our bar would pull out 5 liters of water a day with the (commercial) humidifier. It will likely be like that for the rest of itslife unless you instal and air system that can evacuate the air. ( a simple tubing to outdoors can be enough or leaving the door open .... )
Keep the humidifier going
It's pointless running a dehumidifier and having the windows open! You will never dehumidify the air with fresh humid air coming from outside. One or the or the other, but not both...
First step: Close the windows and do not open them until the outside air temperature is lower than the temperature of the walls in your cellar (not air temperature of your cellar)
Thank you all
Windows have been closed and dehumidifier is running.
The tank takes 14 liter, had to empty it already once today
Recently a painter told me that newer homes have even more of a humidity problem in cellars than older homes.
What you want to consider is connecting your dehumidifier to a drain so the water does not collect in a tank.
Opening the windows in the cellar in this weather is a mistake, as others have pointed out.
Our new-build (delivered 2001) took a couple of years to dry out properly, especially in the cellar... autumn/winter 2000 during construction being particularly damp.
Keep a window open and continue using the de-humidifier for a few months longer. If the problem persists speak to the constructor; possibly there's a construction defect that needs fixing under the 10-year building insurance.
Sorry. Mrs Dolittle is right, keep any window to the cellar closed .
We have that problem too and lots of items were getting mould on them. The builders said that because it is a new building it needs time to dry out, especially the cellar and this could take up to 3 years! We only notice the issues in the summer and I sporadically go down to check stuff and clean anything that needs cleaning. We have no windows down there and I haven't bothered with anything else as the cellar needs time to regulate itself. Good luck.
Our cellar also took a couple of years to dry out.
Other places I know that weren't dried out properly during construction took much longer with paint peeling off walls in upstairs rooms etc.
Two years for a cellar seems normal.
This seems to be a big problem with the Swiss construction. We are in a new building too and had our cellar turn moldy until we were told that the window needed to be opened. It was quite a shock to smell all the mold.
We've been looking at many properties and seen it elsewhere too. Seems to us they are building good quality air tight construction to uncertified MINERGY standards but don 't including the full air exchange for proper ventilation to cut the budgets, but don't cut the sales prices.
If the building is new it will take at least a year to dry out completely. Maybe two, depending on the location.
If part of the foundation is above ground the walls will sweat in the winter due to the temperature difference. The only real solution is to insulate the outside walls and have a 'dampfsperre' installed in the inside wall covered with insulation.
A dehumidifier helps a lot.
The house I live in was built in the 70s and has the same problem
It is also recommended not to put things directly against the outside walls, but leave some space.
Similar advice to others. My workplace is in a new building, and we had to make sure everything was raised and not against the walls, and ran humidifiers regularly down there for the first year...
Year 3 and it's a lot dryer and we don't seem to have any mould issues...
Well, as long as you dont have frogs down there you should be happy. Thats what we had in on place we lived in.
That's kind of funny!
I already found some slime little creatures around there.
This construction is suppose to be according to MINERGY standards, but like you said does not include any full air exchange, unless you count the drafty windows
However having now kept the cellar window closed and the dehumidifier running, I can see a big improvement.
Can anyone recommend a particular brand or model of dehumidifier?
I have some damp patches on the cellar wall, which causes the paint to flake off.
External company confirmed that the patches are not due to water coming in from outside, but due to the house being of older construction (1952) and the walls being cold.
He suggested trying a dehumidifier to see if it helps.
I already open the windows to the cellar and the rest of the house each morning, so it's not a question of no fresh air.
Was considering something like this https://shop.mediamarkt.ch/de/hausha...s/idp989jq6yif
That will do the trick but looks expensive!
Do you have anywhere you can set up a drain pipe so you don't have to keep emptying the tank?
I have a couple of electroline units costing about 130 euro, I use them in Malta when away for several months in the winter, when relative humidity often reaches 90%. I run them on time switches & manage to keep the RH below 65.