Skip to Main Content

Overspanned Floor Joists

Floor joists are integral to supporting your main floor. If they overspan, it can lead to several problems. What can cause floor joists to overspan?

moldy rotten wood joist with rusty jack

What Causes Overspanned Floor Joists?

All homeowners appreciate their fully insulated walls and the roof over their heads. However, hardly any homeowners pay any mind to the floor below their feet. You might notice the odd springy part of your floor or that it seems to slope at points, but not think anything of it.

Believe it or not, this is a sign of structural decay within your flooring system. Most times, it means you have overspanned floor joists that need better support. What are floor joists? What causes them to overspan in the first place?

What to Watch out For

Floor joists are the horizontal pieces of lumber that are used to support your main floor alongside the support beams that elevate it. These joists need to be spaced evenly apart at measured intervals to best support the floor itself, all your furniture, and you and your family as you walk across it every day.

If you notice that your floor has become uneven or is starting to sag, there is likely an issue with your floor joists underneath. Keeping an eye out for any problem signs can be a great first step to preventing these issues from growing worse. What are some problem signs you should watch out for?

  • Bouncy or Uneven Floors 
Closeup of level with hand

Of course, if you notice something is wrong with your floor, then it is very likely that overspanned or sagging floor joists are the cause. Floor joists are supposed to keep your floors nice and level.

Any particularly bouncy or uneven section of your floor can indicate that your floor joists have begun to falter and need extra support. Usually, your floor joists are located within a hidden in-between area in your home known as the crawl space. It is possible that moisture has seeped into this small space and caused your floor joists and support beams to deteriorate in the first place. 

  • Mold Growth
mold on wood in crawl space

Your crawl space can be quite warm due to all the insulation embedded within it. If any moisture seeps into it due to your now uneven floor, the space will begin to grow more and more humid. Humidity within this space can cause all sorts of problems. The most notable of these, however, is mold growth.

Mold spores are extremely tiny and most homeowners only notice they have become an issue when that growth has expanded exponentially across their home. A single visible black spot can contain millions of mold spores that can spread throughout the air in your home.

While not necessarily toxic, the International Association of Certified Home Inspectors states that mold produces allergens that may cause:

  • Fever
  • Skin rash
  • Red or burning eyes
  • Sneezing
  • Runny nose

Family members who suffer from asthma or chronic lung disease are especially at risk for these issues. Mold spores may even infect their lungs, which can be dangerous if left untreated for some time.

  • Water Damage 
Water in crawl space

An uneven floor can give way to moisture trickling in and damaging the important components within the crawl space. You might notice parts of your home leaking or cracks sprouting up from the floor and flooding your home during severe storms.

Even seemingly minimal damage can lead to larger issues later down the line. It is best to take care of any leaks or cracks the moment you notice them.

  • Leaning Infrastructure 
Door stuck to floor

Your floor joists are supposed to keep your floor level, ensuring your walls, windows, and doorways are as well. If your floor joists begin to sag, it is likely your floors will. The loss of support can also cause your walls, windowsills, and doorways to lean or tilt. This can cause your windows and doors to stick, making it harder for you to open them.

Solutions that fit into your life

Causes of Overspanned Floor Joists

Looking out for significant problem signs is a good first step. However, knowing what causes floor joists to overspan in the first place can be a tremendous help in taking steps to prevent it. What can cause floor joists to become overspanned?

  • Moisture 

Moisture can seep into your crawl space if it is not sealed properly. This can lead to all kinds of problems, including overspanned floor joists. Floor joists may shift or crack from the weight of the moisture seeping through its pores. This can lead to uneven flooring, leaning walls, and sticking windows and doorways.

Many floor joists used to support floors in residential areas are made of wood. If moisture creeps into this space, this wood is likely to rot or become a breeding ground for mold. Your crawl space may also take on too much moisture that may seep into other areas around your home.

Cities located within humid climates like Virginia Beach are especially vulnerable to the damage that moisture can create both within and underneath their homes.

  • Construction Defects 

Though moisture is a large contributor to crawl space issues, it is possible that there was an error made during the construction of your house. Floor joists are made to span a certain distance. A contractor could have measured the joists slightly off and left your house with overspanned floor joists that push up against the support beams. Over time, the joists may shift or crack and cause your floor to become uneven.

It is a good idea to hire an inspector to take a look at your floor joists if you suspect any problems within the infrastructure of your crawl space.

How to Repair Overspanned Floor Joists

Your home’s crawl space is the narrow, hollow area between your ground and the first floor. This space is typically only one to three feet high and contains many of your home’s valuable systems, such as the:

  • HVAC system
  • Electrical wiring
  • Insulation
  • Plumbing
  • Your foundation 

Most homeowners may not be comfortable squeezing into such a tiny area, nor will they be able to safely navigate it once inside. It is best to leave overspanned floor joist repairs to the crawl space experts. These experts can easily maneuver through these tight spaces to quickly repair any overspanned floor joists.

Usually, overspanned floor joists just need the right support to bear the weight of your home again. Experts can install these supplemental support beams or foundation jacks such as the IntelliJack™ crawl space stabilizer to better distribute your home’s weight across it. This stabilizer can ensure that your floor joists are properly supported and that no further damage can be done.

Overspanned Floor Joists FAQs

When placing floor joists, the designer and the construction crew need to think about what’s called the spanning of the floor joists. This has to do with how far apart and how thick the floor joists are. Floor joist spanning is nothing if not hugely complicated, which means there’s not a simple answer to the question of spanning recommendations.

  • Factors to Consider for Spanning Joists

There’s no such thing as a simple way to determine how far apart floor joists should be. That’s because there are many factors that a construction crew and designer will have to consider.

For example, the team helping you out may consider the width of the joist, the length of the joist, the spacing between different joists, and the strength of the floor itself. All of these things are important factors.

  • The Importance of Spanning Joists Appropriately

When you span the joists inappropriately, it’s typically called overspanning, which is when the designer or construction crew thought that the joist could hold more weight than it could. This is one of the more impactful joist spanning issues.

When this happens, you’re going to start seeing issues with the floor because it doesn’t have enough support. That can eventually lead to extremely serious problems.

  • The Downfalls of Improperly Spanned Joists

Improperly spanned joists can cause all sorts of problems in and around your home. The most obvious one is with regards to the floor. With improperly spanned joists, you might end up with serious problems.

If the floor joists are too far apart and you leave the problem for too long, you might end up with the floor caving in on itself. It can also have a negative impact on the foundation of the home and the overarching structure.

It might seem strange to put floor joists in the crawl space if you don’t know much about home architecture. However, storing floor joists in the crawl space is one of the best ways to ensure that the floor joists stay healthy. You just need to make sure that you’re doing it appropriately for your crawl space.

  • Essential Components of the Home

The crawl space houses many of your home’s essential components, including your floor joists. On top of floor joists, the crawl space may also include your pipes, your electricity hookups, and much more.

Storing these elements of the home in your crawl space is the best way to maximize accessibility and safety. It ensures that these elements of the home are out of sight, but also available if you end up needing to reach them.

  • The Benefits of the Crawl Space

The crawl space is meant to remain out of the way and completely dry so that nothing is compromised by human interference or moisture. Floor joists in particular must remain dry to ensure they do not decay or shift out of alignment.

When you install these components in a sealed crawl space, you’ll ensure the joists’ longevity. However, of course, you need to make sure that the crawl space is as healthy as possible first.

  • Ensuring Your Crawl Space Is Healthy

The ability of the crawl space to keep your floor joists healthy is predicated on the idea that your crawl space is itself healthy. With an unhealthy crawl space, you’re inevitably also going to see unhealthy floor joists.

You need to make sure that you’re keeping your crawl space as healthy as possible by utilizing concepts like crawl space encapsulation. Otherwise, you’re likely going to end up with serious problems surrounding your floor joists.

An overspanned floor joist is one of the most frustrating problems that you can have in your home. It typically causes sagging floors and other related overarching problems. It can also have a negative impact on the crawl space construction and the overall construction of the home. However, trying to fix this problem on your own is not the right step.

  •  Problems with DIY Fixes

You shouldn’t attempt to fix your overspanned floor joists on your own. You might accidentally damage the other systems embedded within the space in your attempt to fix just one problem.

Additionally, overspanned floor joists can be an extremely complicated problem that needs an equally complicated solution. In an attempt to “fix” your crawl space, your DIY attempts could just make things worse.

  • Getting Help from a Crawl Space Expert

You should leave the repair of overspanned floor joists to the crawl space experts. They’re used to working within these slim spaces without damaging any of the crucial systems they contain.

A crawl space expert will also have the right equipment to permanently support your floor joists. If you’re having issues with your floor joists, definitely get in contact with a Groundworks expert to learn more about your options.

Hiring a Crawl Space Expert

Most homeowners are not even aware of the existence of their crawl space, much less know how to repair anything within it. Its narrow ceiling and stuffy atmosphere can be quite claustrophobic for those unused to traversing such spaces.

Crawl space experts are very familiar with all sorts of narrow passages and can navigate through your crawl space with ease. They will know exactly what sort of plan to implement to ensure your floor joists remain upright and level for years to come.

National Reputation, Local Expertise. Find your local Groundworks company.

search your zip code for a branch