Condensation is a common problem during the winter. As temperatures drop we have received lots of calls from area homeowners reporting wetness around their can lights. In virtually every instance the problem was attributable to condensation. And, in most cases the problem was a direct result of a home humidifier being set too high!
It’s normal to kick up the humidifier during the winter. After all, adding humidity to the interior can really help prevent your eyes and nose from getting dried out. Not to mention the higher humidity levels help reduce static electricity too. But, interior humidity levels should be reduced as outside temperatures fall drastically lower. Otherwise, condensation issues are very likely to occur.
To follow is a chart illustrating recommended interior humidity levels in relation to exterior temperatures. If you follow these recommended humidity levels, your risk of experiencing condensation issues should diminish.
Exterior temperature: | Recommended interior humidity level: |
20 to 40 degrees | not be more than 40 percent |
10 to 20 degrees | not be more than 35 percent |
0 to 10 degrees | not be more than 30 percent |
10-below to 0 degrees | not be more than 25 percent |
20-below to 10-below | not be more than 20 percent |
Venting bathrooms directly into the attic also promotes condensation problems!
Venting bathroom ceiling fans directly into the attic space is another major contributor of condensation problems. Bathroom ceiling exhaust fans should always be vented to the exterior of the home. Regrettably, we find a large number of bathroom ceiling fans to be improperly vented directly into the attic. This not only negatively impacts the performance of the insulation, but can negatively impact the entire attic space, including the roof & roof decking. So, don’t leave it to chance. Give us a call today. We’ll take a look and offer a quote for any work recommended.

Dan Whitfield HCRI-R #201012195