The durability of your flooring can vary greatly depending on its material, quality, and placement. Most homeowners know to be mindful of basic care for carpets versus hardwood. What you may not have considered is the importance of what can’t be easily seen — the subflooring.

Subflooring is the layer located under the finished floor covering that acts as the foundation. Normally, it provides a level surface to support your floors. However, if it’s not taken care of properly, you may run into the following issues.

1. Mold and Moisture


Black mold on wall and floor

When moisture forms between layers of the floor, mold can occur. You’re more likely to find mold in sheet vinyl, laminate flooring or ceramic tile. With carpet, the moisture is more noticeable, and you can take care of it much more quickly.

Some causes of moisture can include faucet or toilet leaks. It is a good idea to double-check that your toilet water isn’t still running for a while after you flush. If the wax ring under the toilet is not secured correctly, water can escape from the drainpipes and affect your subflooring.

Another factor that creates moisture is warm air. While you may have been blasting the heat during this cold and snowy winter, try lowering the heat a little as spring temperatures are coming.

Mold exposure can cause symptoms similar to an allergic reaction, such as a running nose, coughing or sneezing. However, less common symptoms of mold exposure include respiratory infections and digestive problems. Although mold is not often visible under the flooring, you can usually detect it through smell. It has a musty, earthy odor to it.  Another sign of mold is the discoloration of the flooring.

If you discover mold, it might be wise to call a professional. Removing mold can carry risks and requires equipment and experience many homeowners may not have.

2. Cupped Hardware Boards

Cupping is when the floor’s sides are higher than the center and create a concave shape. This often occurs when there is an elevation of moisture content in the bottom of the flooring compared to the top layer. The problem can arise from plumbing issues, appliance or building leaks, or site grading problems. Moisture vapor can also cause problems.

To solve a cupping problem before it creates too much damage, eliminate the source of water, and dry out the floor. Use a combination of heat, air movement, and low humidity.

3. Cracks in Floor Tiles

Cracks in the floor not only make the flooring look unpolished but can also be hazardous if unnoticed. So what causes these cracks? First, any heavy impact to the floor, like dropping a large pot, can create unwanted splits. Usually, this type of disruption affects the edges of the floor rather than the center. Heavier furniture or appliances can also break the floor during the installation process.

Your floor’s structure can also create cracks, like if a contractor spaces the joints improperly or places tiles over the control joint. Do your research to hire a trustworthy flooring contractor so you don’t have to worry about faulty installation of your flooring.

4. Uneven Peaks and Valleys

While walking around your house, you don’t want to feel like you’re climbing up a small hill. Age-related settling can cause an uneven floor, which can be an inconvenience. A way to fix this problem is to apply a cement-based self-leveling floor product.

The problem can be more severe when it stems from structural issues with the foundation or the joist. A way to fix these problems is to replace the subfloor panels with new ones or plane the higher part of the joist until it’s level.

5. Ceiling Stains


Ceiling Water Damage

Moisture that gets into the top floor can leak into the lower level ceiling and create stains. Upstairs bathrooms can often cause these stains since sinks and toilets can have plumbing leaks that develop moisture.

The most important thing is to deal with the problem right away and not ignore it. Make sure to identify the source of the stain before dealing with it. After you fix the problem, you may need to tear out a portion of the ceiling that was damaged to prevent any future harm. Consider hiring a water damage professional if you are uncomfortable tackling the project yourself.

Pay Attention to These Common Subflooring Issues

Your home should be a place of comfort to come home to after a long day, so make sure it is safe and free of any long-term damage. Your floors are an area of your home that require special attention. Be sure to watch out for the common subflooring issues of molding, cracked tiles, uneven flooring, cupped floorboards, and ceiling stains.