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  • All American Inspections

Mold in the Basement?

What causes musty basements?

Houses built before the 1970’s typically weren’t built with features designed to keep dampness out, including:

  • Effective perimeter drain systems

  • Interior drain “tile” systems

  • Sump pumps

  • “Damp proof” or water-resistant foundation walls

Musty smells in basements are almost always caused by mold. The only way to tell for sure if there’s airborne mold in the house is to have a mold inspection that includes air sampling. Let’s explore a few ways that basements can be transformed from dreary, dank, disgusting places into dry, comfortable environments!

#1 – Improve ventilation

Basements in old homes weren’t originally meant to be kept closed up, so I don’t know why people in 2020 want to completely block off airflow to these spaces. Simply cracking the basement windows open can go a long way toward drying out basement walls, and therefore reducing the chance of mold growth. If windows have been blocked off by plywood or other material, then remove it. As a licensed home inspector I’ve seen that many times. It seems that homeowners tend to cover broken windows with plywood (or cardboard) instead of paying to have the window replaced. A better solution to opening windows might be to have a system such as the EZ-Breathe. This system is designed to circulate air between upper levels and the basement, while drying and filtering air at the same time. These systems are typically installed by professionals.

#2 – Remove paneling or drywall in the basement

Many stinky basements seem to have walls completely covered with funky paneling from the 1970’s and 80’s. This stuff may have enabled homeowners to create a party den, or a place to send the kids on Friday nights, but it also can trap moisture.

The eternal desire to finish basements runs strong, but there should be an eternal desire to have the healthiest air quality possible. If the basement hasn’t been properly waterproofed, then don’t even think about creating a man cave, lady lair or party palace unless you’ve first made sure that the foundation is 100% dry. Paneling, drywall and other building materials that aren’t designed for water contact will absorb water and attract mold. Removing this stuff can help a lot with having a dry basement.

#3 – Extend HVAC ducting in the basement

If the house has forced-air heating, then it’s usually an option to have ductwork extended and registers installed throughout the basement to improve airflow. Airflow helps to evaporate condensation and reduce mold growth. Ductwork or even flexible ductwork can be professionally installed for somewhat reasonable prices and can help reduce basement dankness.

#4 – Install a Dehumidifier

So “install a dehumidifier” might be making the fix to the damp basement issue too simple. I notice dehumidifiers sitting in basement corners is over half of the homes that I perform mold inspections at. But I don’t think that small, portable, residential style dehumidifiers are adequate when we’re talking about major humidity levels. HVAC companies such as Carrier manufacture residential dehumidification systems that can remove gallons of water per day from the air, and are designed to be quiet and run continuously. These things can be installed to operate in the basement only, or even the whole house.

#5 = Consider a hybrid heat pump water heater

Almost all water heaters that I inspect for buyers as sellers are 40-gallon, storage tank natural gas systems. These things are the go-to for most plumbing companies. This type of heat pump runs on electricity, but it contains a condenser, just as air conditioners, dehumidifiers and do. Hybrid heat pump water heaters are equipped with both a compressor, and resistance-based heating element. Under most conditions they heat water by extracting heat from the ambient and transferring it to water. Optionally, the system can be setup to use more expensive, traditional electric heat under certain conditions.

The better news for damp basements is that these systems also dehumidify the ambient air as they operate. In addition to having cheaper hot water, your basement might become dryer! Hybrid heat pump water heaters probably won’t fully dry out a very damp basement, but as part of a solution but they make a lot of sense.

#6 – Avoid finishing an un-dry basement

The smartest decision the owner of an older house can make is to correct any issues with dampness and mold in the basement before investing in upgrades elsewhere in the house. Perceived mold problems tend to scare buyers away, so investments to reduce the fungus can go a long way. It makes total sense that people want to convert their basements into living spaces, but so many old houses simply aren’t well-suited for these conversions. Do yourself a favor and don’t even think about finishing your home’s basement unless it’s been proven to be dry and is properly heated during the winter months.

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