Dampness in Basement: How To Check for Mold & Wet Walls

By: Diana Rodriguez-Zaba
Updated on: March 26, 2024

Dampness in the basement sets up a perfect stage for mold growth. It can turn the downstairs into a breeding ground for fungal colonies that permeate sheetrock and ruin wood framing. Airborne mold spores invade ductwork and compromise your home’s healthy air quality.

Do you know how to check for mold and wet walls in the basement?

When you understand the extent of the problem, you can make better decisions about how to tackle it.

We specialize in mold testing for home basements, but we also want to help you keep costs to a minimum – that’s why we’ve put together this guide to help you figure out what’s going on downstairs.

Why There’s Dampness in Basements

You probably don’t think of concrete as porous, but moisture migrates from the ground surrounding your basement through its walls. Heavy rains, existing water tables and even morning dew all contribute to the damp. The results are often areas of white, fuzzy efflorescence on exterior and interior surfaces that you might mistake for mold.

If the atmosphere downstairs always seems damp regardless of the weather, the source might be basement condensation. This condition is caused by high humidity levels inside the basement environment, and it causes the same kind of mold problems.

How to Test the Walls for Moisture

You can’t address damp basement walls until you know where the moisture is coming from. To determine if you’re dealing with an exterior or interior problem, try this simple test (you can also buy a moisture meter, but that requires some more effort and investment on your part).

1. Secure a 12-inch square of plastic to the basement wall with water-proof tape tightly sealing all four edges.

2. Leave your test patch in place for at least 24 hours or preferably several days.

3. Check the plastic periodically to see if moisture forms on its surface. If it becomes wet, then you’re dealing with high indoor humidity.

4. If you find a damp, dark spot under the plastic when you remove it, this means that moisture is wicking through basement walls from the outside.

If the moisture is from outside, you can try a DIY approach with the same techniques that help prevent basement flooding. If moisture is from the inside, you’re usually in luck. You can reduce indoor humidity downstairs by running fans to increase air circulation and installing a dehumidifier. Don’t store belongings against walls, and make sure that the furnace and clothes dryer are properly vented.

Mold Patrol in a Damp Basement

It only takes 24 to 48 hours for mold spores to transition from airborne microorganisms to an unhealthy growth. Once it takes hold in the basement, you’re facing a big DIY cleanup project. Stay ahead of potential problems by regularly checking these areas for signs of mold growth:

  • Behind baseboards and in dark corners
  • Spaces around furnace and clothes dryer vents
  • Flooring under the washing machine or laundry sink
  • Finished walls where pipes might leak

Ceiling areas directly under the kitchen and bath

When you discover a suspicious fuzzy patch, test it with several drops of bleach applied with a cotton swab. If the area lightens after a few minutes, it’s harmless mildew. If it remains dark, you’re dealing with mold.

DIY Waterproofing Options

With regular basement inspections, you can stay in front of most mold problems before they cause serious damage. It only takes a few minutes, so put a downstairs checkup on your monthly to-do list of household chores.

If you can’t control basement moisture, consider waterproofing the downstairs. Options run from silicate-based sealers and acrylic paints to plastic paneling and upgraded drainage systems. Whether you take it on with your DIY talent or call in professionals, this type of home improvement project is a smart investment in a dryer basement, fewer mold problems, and better health for the entire family.

Serious Caution Signs

While you can handle most mold cleanup jobs in the basement, it’s important to understand that the project can be dangerous. Without certified testing, you don’t know if you’re dealing with ordinary fungal growth or toxic black mold. Don’t try to do it yourself if:

  • The affected area covers more than 3 square feet.
  • Mold growth permeates porous materials and surfaces.
  • Mold removal requires tearing out walls or flooring.
  • Anyone at home suffers with health issues especially respiratory problems.

If you have any doubts about basement mold cleanup, play it safe, and let industry-certified specialists take care of the job. Don’t risk damaging your property or endangering your health.

We’re Here to Back Your Efforts

mold remediation services

Once you know how to monitor dampness in the basement, you can minimize the chances of unhealthy mold growth taking over the house. We hope our guide helps you deal with this downstairs problem, so let us know if you’d like more information. We’re always here to answer your questions through our Comments Section.

We’re also here to back up your DIY efforts at your home or business. Our teams stand ready to tackle every type of mold problem with certified removal and remediation services.

Just call Service Master Restoration by Zaba today for the very best mold inspection in Chicago and the surrounding suburbs.