I noticed this morning that my basement humidity level and temp were 63% and 77 f . Outside was 78f and 89% humidity. I have 90% of the basement with a vapour barrier and stone on top. I also have a dehumidifier down there. Is there anything else I can do to get the humidity level down. I could run the dehumidifier longer or set it on high. Any thoughts other than putting concrete down?

 

Is the basement humidity a problem? Is there a musty smell or is water condensing on things?

How is the rest of the house?

Do you have central ac? Is the basement air conditioned?

You are already lower than the outside stats. Unless the humidity is causing problems, I'd not worry about it.

 

It's not a problem yet. We built the house and have been in it about 5 months. I just want to make sure that I don't get a mould or dust mite problem. I have a shop down there so like most do it yourselfers, I'm always down there fidlin

 

Humidity should be maintained between 45-55%. This can be confirmed with a humidistat. An additional or large humidifier to accommodate the square footage that needs dehumidified may be required.

Mold and mildew spores are everywhere. They tend to propagate in areas that are dark, damp, and unventilated. Running fans keeps basement air circulating and dehumidfiers keeps humidity levels in check.

 

I am curious about one of your remarks where you said should you run your dehumidifier longer. I keep mine on 24 hours a day.
Most I know do that also. They take very little electricity. Also, you could put box fan in your basement and keep it running. This will dry out the air also. As far as dust mites go, you already have them. In your carpet, couches, matress's etc. They just come with the territory. Just some thoughts. Good Luck

 

I have an air conditioner in the basement window here and run it when i get home from work 2:30pm till about 9pm each night. I find it works better then a dehumidifier and its cheaper to use. Right now the humidity has been high outside, plus its raining and the basement is running at 43% @70F

 

we are building a house at the beach in new york. in april /may with the monsoon rains we had, not a drop of water. now in july/aug with little rain, we have some puddles in the basement which the builder says in condensation. since we plan of finishing it this winter, what steps do we take to ensure there is no moisture ?? -

is this the builders responsibility to make sure we have a dry basement on delivery of the c.o. to us??

thanks

 

http://www.epa.gov/iaq/schools/tfs/guideh.html

This is an EPA webpage on preventing mold and mildew by controlling moisture. It discusses what are the sources of condensation and how to address it. In other words to prevent mold and mildew from occurring, you must control the source of the moisture.

This site really does not discuss basements but it does give the reader an idea of the factors concerning mold and mildew growth within structures. Of course the conditions in the home differ than in your basement. However, by understanding how moisture enters the structure allows you to best address the problem.

For example, Hellrazor's reply concerning the use of an air-conditioner and he finds it to work better and cheaper than a dehumidifier. He/she is absolutely correct and the EPA website gives you the reason why. Both the dehumidifier and air-conditioner remove humidity in the air when the basement air passes through their coils. The difference between the two is that the air-conditioner diminishes vapor pressure through circulating the air in the basement far better than the dehumidifier. Whereas removal of humidity in the basement does not address a source of humidity in the basement but diminishing vapor pressure through circulating the air does. So the use of an air-conditioner in fact will not only do a better job but will also be cheaper to use than a dehumidifier in this application, simply because it addressses a source of the humidity in the basement.

Though an air-conditioner may not be your best choice in your situation, the EPA website does give you some ideas on how to control moisture within the structure. When it comes to acceptable humidity levels within a structure, basements will always have a higher level. This is because of the ground surrounding the basement, which can be described as having an endless supply of moisture. So having high humidity levels in basements are not unusually. The problem with mold and mildew arises in basements occur when other applications are introduced to the basement, like insulation. Especially when the sources of the humidity in the basement are not addressed.