Common Causes Of Moisture In The Attic

Attic clean up professionals always look for signs of moisture in attics, and homeowners should regularly do this as well. While many homeowners usually associate dampness with basements or crawl spaces, attics can suffer from moisture problems just as easily, which can lead to damaged insulation, structural issues, and problems with mold.

Common Signs of Moisture in Your Attic

  • musty smells
  • frost
  • ice on cold surfaces in the wintertime
  • foggy windows
  • condensation on windows or other smooth surfaces
  • visible mold
  • wood rot
  • the deterioration of masonry
  • the staining, discoloration or warping of construction materials

If any of these signs are apparent, it’s best for homeowners to determine the cause right away and fix the source of the moisture before it causes expensive damage.

How Did Moisture Get In My Attic?

Unfortunately, finding the source of moisture can be a difficult task, even for attic clean up specialists. One sign of excess moisture can be created by several sources, while one source of moisture can create multiple, seemingly unrelated signs. Here are some of the some of the common causes of attic moisture that attic clean up professionals will usually evaluate first:

Roof leaks

These leaks may be small enough that evidence of water damage is not yet visible in the home’s living quarters. Attics are often one of the first places to show signs of a leaky roof.


Pipes that run through the attic can sweat and leak. The pipes should be checked to ensure that water vapor is not condensing on cold pipes and that the pipes are not dripping.


Believe it or not, water in a home’s foundation can create signs of moisture in the attic. Water in the ground can easily travel through the basement or crawlspace floors and walls. This water then evaporates into the air inside the house and travels to the attic through “bypasses” – any area where warm air flows into the attic. These bypasses can be anything from openings around light fixtures to cracks in the ceilings, and these seemingly small passageways can allow enormous amounts of warm, moist air into the attic.

  • Ventilation to the exterior: Attics should be properly ventilated to the outside so that moist air does not become trapped. This is particularly important during times of high outdoor humidity. However, sometimes attic ventilation systems stop working or become blocked by debris such as leaves or animal nests.
  • Interior ventilation. Moisture from appliances like clothes dryers – and from areas like the kitchen and bathrooms – commonly leads to problems in the attic. Sometimes, ventilation pipes are inadequate or become disconnected. In these cases, the warm, moist air is being pumped into the attic, rather than being carried to the outdoors.
  • Air conditioners. Air conditioners typically operate by sensing the indoor air temperature, not the humidity level. If the indoor temperature drops enough and the humidity stays high, moisture can condense on the ducts that move the chilled air. This is common with air conditioners that are too powerful for space.

There’s more to keeping your home safe and mold-free than attic cleanup; you also have to consider what’s below your house. If you are experiencing moisture issues in your home, you may need to examine and clean up your crawlspace. Read on to learn the simple steps ofcleaning up crawlspace moisture.

How to Clean Up Moisture In Your Attic

Step 1: Inspecting the Area

The first thing you need to do is find a way into the crawl space. Often, there is a small door through the foundation on the exterior of the home, though some homes have an interior trapdoor. If you cannot find a way in, contact a professional. Once you are in, take a look around. You should look for water, mold, or damp insulation. These are all signs of crawlspace moisture.

Step 2: Removing Affected Materials

First, remove all the debris and insulation. Be careful to take safety precautions when dealing with these materials. Next, you need to get any standing water out by using a sump pump. Finally, remove all contaminants such as mold or asbestos. It is wise to contact a crawlspace and attic clean up professional to advise or assist you in proper removal of these contaminants.

Step 3: Eliminating Moisture

Set up a dehumidifier and place several fans around your crawlspace. Direct the fans on damp areas around the walls, floor and ceiling. These will help to increase the dehumidification rate by improving airflow.

Step 4: Maintaining Low Moisture

Addressing any drainage issues is the first step to maintaining low moisture in your crawlspace. Also, since most crawlspaces have dirt floors, a considerable amount of moisture can be prevented with the addition of a crawlspace vapor barrier. To find out if vapor barrier insulation is needed in your home, consult a professional insulation installation service.

How To Get Rid of Your Attic’s Moisture

If you think the ideal conditions for mold and mildew are present in your attic, there are a few at-home tests you can perform to gauge the moisture level.

Step #1: Consult a thermometer.

An excessively high temperature in your attic allows the air inside to hold more water vapor. Depending on the climate and level of insulation and ventilation in your attic, temperatures can reach up to 150 degrees Fahrenheit. To properly gauge the temperature of your attic, you should use three thermometers – one in the middle of your attic, one near your attic entry and one at the far end of your attic – then record and take the average of these temperatures. Based on your location, a significantly high number could indicate a potential moisture problem – especially when hot, humid air is allowed to cool and create condensation.

Step #2: Check for excessive moisture.

While there is a special device, called a hygrometer, that can measure humidity, this instrument is not a common household item and can be hard to interpret. Fortunately, you should be able to gauge moisture levels in your attic via a visual inspection. If there’s condensation on attic windows or surfaces are wet to the touch, the humidity of your attic is too high. Colored spots, musty odors and other signs of mold can also be detected with simple observation.

moldy insulation

Got Moisture In Your Attic? Atticare Can Help

A nationwide company serving the San Francisco Bay Area, Northern and Central New Jersey and the Los Angeles Area, Atticare provides attic cleaning and insulation services to remove mold-damaged insulation, minimize temperature fluctuations and improve humidity control. If you think your home has a mold or moisture problem, schedule a free consultation with Atticare. Call us at 1-866-692-5449 to book an appointment.

Updated: 7/23/20 at 11:00 am


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