Builder Tip 2 - Heat & Ventilation in the Summer

Question - We seem to be getting mildew and even some light mold in our basement.

Suggestion - Weather is hell on a home and even more hell on a home that is not lived in full-time, since the act of living in a home invites air circulation and fresh air into a home.  With super-sealed envelope from our enhanced insulation which results in comparatively low heating and cooling costs comes a side issue of ventilation, or actually lack thereof.

In basements, there is no substitution for a good dehumidifier running all the time - by running all the time I don't actually mean 'running all the time' - I mean being set to a dehumidification level on the machine that provides for it to kick on and off as needed - and these requires 2 things for success - a good dehumidifier and a place to drain the water being sucked out of the air.

A good dehumidifier will run $300+ - you get what you pay for, especially with dehumidification.  Also, you don't want to depend on the internal pump that is supposed to pump the water up (against gravity) and out a window - they don't seem to last for long.  So the drain line out of the dehumidifier should drain into a laundry drain (with the machine elevated) or a hole in the concrete floor of the basement.

It's always good to air out a basement on occasion - so when you are up, open up the doors and windows of the basement and get some good fresh air down there to replace the dank, moisture-ridden, subcavernous, stale air that is naturally lurking in a space like this.  A fan isn't a terrible idea either.

For those homes without basements or with finished basements, the necessity is even more real, since while an unfinished basement will naturally 'leak' some air, a fully finished and lived in basement will prevent some of that passive air leakage, creating a more urgent need for ventilation, and dehumidification.

Hot summer months in a locked up, windowed up, non-air conditioned home are when the humidity can really cause some problems, and there is no real secret to keeping it from happening - and that is adequate dehumidification.