Replies

1. 
   user-2310254 | Aug 30, 2016 02:28pm | #1

   Heather. Where do you live? What type of insulation was installed in your crawlspace. How large is your crawl space, and what size fan was installed? Is the fan always on and does it vent to the outside?

2. GBA Editor
   Martin Holladay | Aug 30, 2016 02:35pm | #2

   Heather,
   Possible source of moisture include:

   1. A damp crawl space.

   2. Overventilation -- a mechanical ventilation system that introduces too much outdoor air into your home.

   3. Too many houseplants.

   4. A hobby like keeping tropical fish -- especially if you have many, many fish tanks.

   5. Storing firewood indoors.

   6. Mopping floors frequently.

   7. Taking lots of showers without operating the bathroom exhaust fan.

3. GBA Editor
   Martin Holladay | Aug 30, 2016 02:37pm | #3

   Heather,
   You told us that you have an HVAC system, but you didn't describe what you meant by that.

   1. Does your home have air conditioning?

   2. Does your HVAC system include ventilation with outdoor air? If so, describe your ventilation system.

   3. At what temperature do you set your thermostat?

   4. Do you ever leave the windows open?

4. 
   Fish9 | Aug 30, 2016 02:37pm | #4

   I live in Wake Forest, NC. The first floor of my house is about 2500 sq. ft., with 2500 sq ft in the crawl space. The house has an upstairs bonus room (approx. 600 sq ft) and a full attic.

   Unfortunately I can't answer the other questions at this time. I will get back to you with those answers tomorrow.

5. 
   Fish9 | Aug 30, 2016 02:45pm | #5

   Yes, the home has a/c. The thermostat is kept at 72 degrees. Windows are only left open in spring and fall. They have not been open since probably May. The HVAC does not include ventilation with outside air.

6. 
   Fish9 | Aug 30, 2016 02:50pm | #6

   Martin,
   Of the possibilities that you listed, none would apply.
   1. The crawl space is dry
   2. No outside ventilation
   3. Only 1 houseplant
   4. No relevant hobbies
   5. No firewood
   6. Mop maybe once / month
   7. Only one person living in house so only one - two showers per day. Also very little cooking and laundry.

7. GBA Editor
   Martin Holladay | Aug 31, 2016 04:19am | #7

   Heather,
   Steve gave you good advice. While the source of your indoor humidity is unclear, it never hurts to operate a dehumidifier. In your case, you might want to operate two dehumidifiers -- one in the crawl space, and one upstairs. The dehumidifiers will lower your indoor humidity level as you wait for specialists to figure out why your house is so damp.

   Here is a link to a relevant article: Preventing Water Entry Into a Home.

8. 
   user-2310254 | Aug 31, 2016 10:15am | #8

   While you are trying to identify the underlying cause of your home's high humidity, you may want to install an Energy Star rated dehumidifier. Most big box stores sell them.

9. 
   Jon_R | Aug 31, 2016 12:16pm | #9

   Air is being provided to the crawl space by the hvac system and a fan was added.

   Remove the above and stick a dehumidifier in the now sealed crawlspace. Also figure out why the AC isn't dehumidifying the living space adequately.

10. 
    AlanB4 | Aug 31, 2016 12:46pm | #10

    Are there leaks in the water pipes or drainage? Sometimes pinhole leaks can form in the walls or other hidden places.
    You can take a picture of the water meter in the evening after all use is completed and the next morning before any use to see if any water is mysteriously unaccounted for. This can also mean slow toilet leaks which are not a possible cause (but a good idea to fix). Drainage leaks will require detective work and some luck.
    Also roof leaks are possible, and depending on the frequency and duration of rain also hard to track down. If this can be checked with a good soaking from a garden hose it may reveal shingle or flashing defects. This is also detective work and some luck.