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Sagging Floors

When moisture gets into your crawl space, it breaks down wooden structures that support your floor. As a result, sagging floors pop up throughout your home.

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Every piece of furniture in your home relies on the floor for support. In much the same way, your floor relies on the crawl space foundation for support. If moisture gets into your crawl space, it causes the structure to become weak. This makes it much harder for the foundation to support your floor and you’re left with sagging floors throughout your house. However, FSS has crawl space support jacks and moisture control tools that prevent this problem sign for good. 

Sagging Floors Explained

Sagging floors arise as a result of high moisture in your crawl space. Humidity and standing water in your crawl space are absorbed into wooden floor joists and support beams which keep your floor level. When these structures get damaged, it leads to sagging floors.

When sagging floors occur in your home, you’ll notice that the floor feels bouncy or spongey as you walk around. Additionally, sagging floors may jam doors or cause them to drag as sections of the floor become uneven. You might even notice cracks across the ground or your floor sagging more in the middle of your home. No matter how a sagging floor presents itself, calling a professional when you notice it is important.

What Causes Sagging Floors?

Soil Washout

While soil washout is generally associated with concrete problems, it can still affect your crawl space foundation and lead to sagging floors. When water drains into your soil from rain, bodies of water, or even sprinklers, it displaces soil and moves underground. Eventually, this groundwater travels into the soil below your crawl space where it evaporates and causes humidity levels to rise. Over time, the humidity leads to wood rot in your floor boards and other support beams below your home. As their structure breaks down, your floor sags. Using interior waterproofing from FSS stops soil washout from affecting your crawl space. Drains installed below your home move groundwater away from the foundation before it has a chance to cause damage.

Crawl Space Vent

Open Vents

Most crawl spaces were built with open-air vents along their walls. Unfortunately, these vents allow humid air to easily enter the crawl space, especially during the summer months when Austin and San Antonio see an increase in humidity. Humidity in your crawl space is always a red flag, as it leads to various crawl space problem signs such as mold or wood rot. More directly, the humidity from outside breaks down wooden structures in your crawl space and leads to a sagging floor. Using a vapor barrier, crawl space vent covers, and a dehumidifier, keeps your crawl space permanently dry and your floor permanently supported.

The Stack Effect

A common occurrence in any building is the process known as the Stack Effect. Essentially, this states that warm air will always rise through a building until it can escape through the highest point. In residential homes, that’s usually through the attic or roof. The Stack Effect starts in your crawl space. Humidity rises due to outside sources such as weather. The air heats up in your crawl space, which forces it to travel up through your floor. Then, it spreads throughout the rest of your home until it escapes through the roof. During this process, tons of humid air is making contact with your floor which breaks down the wood and causes it to sag. Thankfully, this phenomena is easily combatted by solutions from FSS. Specifically, vapor barriers prevent the stack effect from transferring humid air into your home.


Yes, for a couple of reasons. First, sagging floors can become a tripping hazard for anyone living in your home – particularly children. Without a flat floor, simply walking across the house could be unsafe. Next, a sagging floor indicates a structural problem in your crawl space. If left unchecked, this could spread into other areas of your home. Eventually, your floors and walls could collapse without the proper repairs. Finally, sagging floors make it much harder for your furniture and appliances to stay level. Over time, these items could tip over, potentially causing injury or damage to your home.

Sagging floors require professional solutions in order to be properly lifted. FSS uses crawl space support jacks to level your floor. These tools can fit in any crawl space thanks to their adjustable design. Manufactured with galvanized steel, these support jacks are rust-proof and durable. You’ll also want to invest in crawl space encapsulation, which prevents moisture from damaging your floor in the future. We don’t recommend attempting to fix your sagging floors on your own. DIY options rarely address the actual causes behind a sagging floor and navigating your crawl space can be dangerous without the proper training.

That all depends on your individual insurance plan. However, most homeowners’ insurance policies have specific requirements when it comes to crawl space damage. Generally, any damage that is caused by uncontrollable circumstances (hurricanes, flash flooding, etc.) will potentially be covered by your plan. Damage that is caused by a preventable circumstance such as old floorboards or a leaking appliance, will probably be seen as “neglect” by the insurance company. Make sure to check with your insurance company for the exact specifics if your home is suffering from sagging floors.

How Does FSS Fix Your Sagging Floor?

While a sagging floor certainly seems daunting to repair, our experienced team has the tools to get the job done right every time. In fact, our technicians have over 20 years of experience when it comes to repairing problems stemming from your crawl space like a sagging floor.

We install crawl space encapsulation measures to ensure that moisture can’t break down floor joists. This includes vapor barriers and vent covers, which protect your crawl space from outdoor humidity and create a controlled environment below your home. We also install interior waterproofing such as drains and sump pumps to move liquid water away from your home after a storm or internal leak.

Additionally, our team installs a dehumidifier to continuously remove humid air from the crawl space. With all of these solutions installed, your crawl space and floor joists stay permanently dry. You won’t have to worry about a sagging floor ever again.

Explore Solutions

Even though sagging floors can look unnerving and dangerous, our solutions ensure that they won’t cause trouble for you ever again. With crawl space support jacks and full crawl space encapsulation, FSS keeps your floor supported and protected from moisture. Without these solutions, your entire floor is at risk for collapse. Invest in crawl space solutions today and let our team keep this problem from happening in the first place.

Keep Your Floor Supported with FSS Solutions

Our team has been dealing with sagging floors in the San Antonio and Austin areas since 2017, and our experts have over 20 years of experience in the foundation industry. Homeowners trust us to get the job done right every time. All of our crawl space solutions are manufactured in the USA for the highest quality available, and we’re accredited by the Better Business Bureau, the Texas Construction Association, and Home Advisor. Contact us today to learn more about our crawl space repair and to schedule a free inspection with one of our technicians.

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