15 May Preventing Moisture Problems Before Finishing a Basement

A finished basement adds so much value to your home. Whether you need extra room for your growing family, a guest room that offers a little more privacy, or a home gym to keep you healthy, a finished basement is one of the best renovations you can make to add personal value and resale appeal to your home. But, not if you don’t guard against moisture problems before finishing your basement.

Moisture is one of the greatest threats to a basement, finished or unfinished. But once you hang drywall, lay flooring, and begin the finishing work in earnest, you trap that moisture. Not only will the trapped moisture cause degradation and damage, but it may also pose a health risk to your family should mold begin to grow. Preventing moisture problems before finishing a basement is essential to your home and health.

Where Does the Moisture Come From?

The first step in preventing moisture problems is to find out the source of this nuisance. The two primary sources of moisture in a basement are water intruding from the outside, such as through a poorly sealed foundation, improper drainage, and sloping ground. The second way is from humid interior air. This can be due to unsealed concrete flooring or poor vapor sealing. 

Your moisture source may be one or the other, or more commonly in the Quad Cities, both to a degree. By identifying which one you’re dealing with, you can begin preventing moisture problems. Here is a simple way to identify the source of your moisture:

• On all four sides, completely tape a piece of plastic sheeting to your bare concrete wall. For a walk-out basement, use the wall that is under the ground.
• Wait 48 hours.
• Check to see if the plastic has condensation on the wall-facing side (outside moisture), the room-facing side (internal humidity), or both.

Preventing Exterior Moisture Problems

Moisture problems can begin outside your home and work their way into your basement. Here in the Quad Cities, we experience all four seasons. That means melting ice, torrential rains, and intense summer heat. If your gutters clog, or your ground has shifted and slopes toward your home, rainwater can be channeled directly at your foundation walls. 

The good news is these are reasonably inexpensive to fix. Clean your gutters regularly and position downspouts four to six feet from your home. Walk around your house and look to ensure your ground isn’t sloping inward. If it is, build up the soil at least one inch per foot for six to eight feet away from your home. If necessary, regrade the yard, install landscape trenches, or catch basins where water builds. 

Foundation cracks are a fairly common issue, but they can cause moisture problems in your basement. Water may seep through even without notice. The best thing to do is to seal every crack with fast-setting patching cement or polyurethane caulk that’s specifically formulated for basements. Pay attention to areas where pipes and wires pass through the wall. There are usually gaps around those places. 

Once you’ve sealed the cracks and prevented water from getting in, add an extra layer of protection by painting the walls with waterproofing paint or using a masonry sealant. This will help with any minor moisture issues after drainage issues and foundation wall cracks.

Controlling Humidity

If you’re fortunate enough not to have any drainage problems or cracks where water can get in, you may still have moisture problems. This is usually due to high relative humidity (RH). And it doesn’t take much to support mold growth. The target RH range is 30% to 50%.

To identify the humidity levels in your basement, it’s necessary to run the right size dehumidifier and verify the RH using a hygrometer. For accuracy, take this measurement over the course of a few weeks, during the wettest season, typically spring into early summer in our area. It’s also important to make sure your dehumidifier drains directly into a floor drain and not a bucket or pan, as that will influence the relative humidity.

Choose the Right Building Supplies 

Once you’ve tackled preventing moisture problems, you can begin finishing your basement. Experts recommend using certain materials to keep moisture out while creating the finished basement of your dreams. From insulation to drywall to pressure-treated lumber, Seiffert Building Supplies has exactly what you need to finish your basement. 

If you have questions about preventing moisture during a basement finish or any other home project, don’t hesitate to get in touch with your Quad Cities professionals at Seiffert Building Supplies.

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