Mildew odor in the closets

[Timothy]

I bought a 60-year-old house two years ago. A new roof was installed by the owner.

I am now noticing a mildew odor in the closets. It has been very humid.

Can an improperly installed roof be the cause? It does not leak.

[home improvement guy]

Any changes you make to one area of a home might have an effect on another area of the home. Also one person's living habits as opposed to another can affect the home. Can a new roof cause mildew? It's not the roof as much as it might be the roof-to-attic ventilation.

If additional ventilation was installed on the new roof or ventilation was removed, it could change the airflow and pressures inside the home. By changing the airflow, you may also change the humidity levels inside the home. Also, as a new owner you may be producing more moisture by having more people in the home, bathing more often, doing more laundry, cleaning more often, cooking differently, etc. All human activities create moisture; even breathing releases moisture.

Usually a mildew odor in a closet results from poor airflow due to excess storage or clothing stacked too tightly up against an uninsulated or under-insulated exterior wall. Without proper airflow, moisture can form between stored items and a cooler exterior wall. This generally happens on the shaded side of the home. Try moving some items away from the exterior wall and leaving the closet doors open to promote airflow.

If you can see the mildew or mold, simply use a tack cloth or brush it off with a stiff brush while using a vacuum to clean the spores. A vacuum with a HEPA (high efficiency particulate air) filter works best. Do not clean with bleach or other liquids. If you notice the odors but cannot visibly see the spores, place a dehumidifier near the room to remove excess humidity and keep the air conditioner at 75 degrees or less to help remove moisture from the air.

The dehumidifier should be set between 50 and 60 percent humidity levels. The dehumidifier will have a catch pan to collect the moisture and will need to be emptied often. A small pump can be used to remove the water from the pan to an approved location.