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Crew installing vapor barrier in crawl space encapsulation

Over Spanned Joists

If your floor becomes uneven, it’s possible the support beams underneath are failing to provide the right support. What can cause these beams to fail in the first place?

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When you notice slight dips along your floor in Toledo and Cleveland, Ohio, this is often a sign of a much larger issue. The same can be said if any parts of your floor seem to bounce instead of lying flat. An uneven floor can present several issues for you and your family. Most people will be concerned that their floors will become a tripping hazard. While this is true, an uneven floor is also often a sign that something is very wrong with an important system underneath your feet.  

Your support beams (also known as joists) carry not only your floor but the weight of everything else on top of it. It is absolutely critical that these joists be built in a precise manner that allows them to distribute this weight evenly across.  

Because these joists are installed within the crawl space, however, it presents an even greater issue when something happens to damage these joists. Unfortunately, sometimes damage occurs due to a construction error that is beyond your control. The joists themselves might be overspanned or too large for the span they should run across. Let’s take a closer look into what can cause your floor joists to be over spanned below.  

What Are Over Spanned Joists?   

Basically, a joist is constructed with several things in mind. The first is the type of room the joist will help to support. Another thing a contractor will consider is the average weight (also referred to as a load) a specific room will hold. Rooms on the first floor typically have higher load requirements than the rooms built upstairs. A bedroom will not bear as much weight as a garage full of cars, after all.  There are two different types of loads joists will typically have to bear: dead and live. Dead loads are basically the weight of the building materials used divided by the square footage these materials are spread across. Live loads, on the other hand, make up everything else in your house, including all your furniture, you and your family, as well as other belongings of yours.   

Different rooms will also require different joist spans. These spans will not run from one edge of the house to the other. Rather, the spans will run from support beam to support beam, the spans of which will depend on the species of lumber, size of the overall house, and local building codes. Despite all this, it can be very simple for a contractor to make a mistake in measurements. Typically, a contractor will consult a simple joist span table when creating the floor joists for your house. Though these guides work well enough, sometimes circumstances will call for a contractor to build a shorter span. The contractor might simply build to the minimum code requirements and leave it at that. This can lead to the floor joist being overspanned, and thus resulting in bouncy, sagging, or uneven floors in the future.  

The joists then being installed within the crawl space makes these mistakes even harder to spot. Many homeowners might not even notice an issue until the damage has run its course. Trusting the crawl space experts at Ohio Basement Systems to repair these overspanned joists is the best thing you can do. Our team will be able to repair any overspanned joists and the damage that they can cause with ease.   

The Damage Overspanned Joists can Cause  

So, as you can see, overspanned joists are a real problem for any home that they are impacting. Because of their placement, the best way to recognize overspanned joists is by the secondary damage that they can cause to a home. These issues can be considered problem signs as well as problems in their own right. The issues most likely to be caused by overspanned joists include, but are not limited to;  

Warped or Bouncy Floors    

Of course, the most obvious sign that something is wrong with your floor joists is if your floor itself is uneven in places or bounces. This does not only present a dangerous tripping hazard for your family, but it can also indicate that your support joists are starting to fail or even rot away. Overspanned joists are one of the most likely causes of bouncy or sagging floors in a home, but there are some other issues which could contribute to this so it is best to investigate fully.  

Floor and Wall Gaps 

If you notice the formation of gaps between your walls and floors, it is highly likely that you have overspanned joists in your home. These gaps can form for two main reasons; because your walls are moving, or because your flooring is moving. If there are no visible signs of damage and deviation in the walls, it is most likely that these gaps have formed as a result of overspanned joists and the steady deterioration of your property’s flooring.  

Collapsed Flooring 

The collapse of impacted flooring is one of the most serious forms of damage that overspanned joists can cause. Thankfully, this issue tends to only occur after a prolonged period of time – if you act when you see cracked, warped, or sagging flooring in your home you should never experience a floor collapse. However, if a floor with overspanned joists is forced to deal with a sudden increase in load, it is possible that the joists could give under the extra weight and allow the flooring to collapse.  

Causes of Overspanned Joists  

Though being able to catch problem signs as they appear is helpful, it unfortunately does little to mitigate the damage that has already been done. Recognizing what can cause damage and overspan in the flooring joists within the crawl space, on the other hand, might prove to be even more useful to you. 

Construction Errors 

The floor joists in your home are constructed in a specific way to properly balance out the weight of your house and all your belongings while allowing for the most space possible. Basically, laying down floor joists is no easy task. It requires incredible precision, planning, and skill to cut even one joist to size.  

Of course, contractors are only human. Sometimes they will make mistakes. This can include a mistake in properly positioning your floor joists. Over time, these misaligned joists could make your floor sag, bounce, or become otherwise uneven. No homeowner wants any creaking or uneven floors. It can be more than a simple annoyance; these uneven parts of your floor can prove to be quite disastrous for your home’s health the longer you ignore them. 

Overspanned floor joists are difficult to repair on your own. It is possible that multiple floor joists will have this issue, which means you will need to measure out and plan the spacing and spans of multiple, heavy support beams. It is very easy to accidentally nick a part of the joist, which can lead to improper support and even more issues with the joists later on.  

 Crawl space experts can also install the best solutions to protect your home from any issues in the future as well. This includes the four parts that make up the encapsulation process as well as other powerful solutions that can keep your crawl space dry and clean. This thorough system will ensure that your home will not face any moisture issues, mold problems, or over spanned joists at all.   


Moisture is a huge issue for all crawl spaces and can contribute to the formation of over spanned joists. Not only can it damage the vital systems stored within, but it can also lead to other issues cropping up around your home as well. Severe storms, humidity, or other forms of moisture are all common weather patterns in Ohio. This can then lead to plenty of moisture buildup in an unprotected crawl space.  


Where there is moisture, rot, and other issues are sure to follow. Mold, mildew, and pests all love especially moist environments. This is what makes the crawl space the perfect shelter for them to grow or breed in. Your insulation is typically stored within the crawl space, which can then create humidity that mold and mildew will thrive in. These fungi can easily overtake your wooden floor joists and cause them to rot.  

Many different pests (though mainly insects) also tend to flock toward homes with moisture issues. With much easier access to a water source, these pests will be far less likely to leave your home. Some pests, such as cockroaches, can also emit a musty smell that will attract others of their kind to your home. No homeowner wants to deal with any sort of infestation, much less one that will draw even more pests to their house.   

Shifted Foundation  

Moisture on its own can wear down your joists and shift your foundation – any movement in your foundation carries a risk of damaging flooring joists. The now weakened joists will be more susceptible to splitting apart or other types of damage.  

Additionally, a shifted foundation can also cause other aspects of your home’s infrastructure to shift as well. This can include these already weak floor joists, doorways, windowsills, walls, and more. You definitely do not want any of these crucial structures to sway or break down. Most homeowners will not be able to locate their crawl space, much less repair such an essential component inside it.  

If you notice any issues with your floor or basement whatsoever, then it is time to call the crawl space experts at Ohio Basement Systems. Our experts have plenty of experience inspecting and working in these tight spaces, so you will not have to. We can also implement any repairs your crawl space might need, all while protecting your space from any future damage.  

Preventing Over spanned Joists and Repairing Crawl Space Damage  

When your crawl space has problems such as over spanned joists, you can trust that Ohio Basement Systems has the solutions you need to protect your home. We have a four-step encapsulation process that can completely protect your crawl space from any moisture, pests, and debris that tries to infiltrate this important space.   

Crawl Space Sump Pump  

Should any water flood your crawl space, the sump pump will automatically activate and pump any water out again. This pump requires very little maintenance, so you will not have to do anything but replace its battery every now and then.  

Vapor Barriers  

This 20-mil barrier will line your entire crawl space to ensure that no moisture, pests, mold or mildew spores, or other issues can infiltrate this crucial space.  

Vent Covers  

Our experts will then close up any open ventilation around your crawl space with our sturdy plastic vent covers. These covers are guaranteed to repel moisture and never rot no matter what.  


Dehumidifiers will filter the air around your enclosed crawl space, ensuring that it stays clean and dry no matter what. Because your HVAC system is also inside your crawl space, you might also find that the air inside your home might become clearer as well.  

Over Spanned Joists


The average height of a crawl space can measure anywhere between one to three feet high. As its name implies, this is just large enough to crawl around.

The main purpose of the crawl space is to store your home’s vital systems inside it. This includes your HVAC system, insulation, electrical wiring, plumbing, and floor support beams. These systems should not be wet whatsoever, which can be a problem when moisture inevitably does enter this space. The crawl space needs to be completely dry or you risk these systems breaking down and causing even more problems all around your house. 

Our team at Ohio Basement Systems can help you protect your crawl space and home with various solutions including a vapor barrier, dehumidifier, and much more.

The encapsulation process is one of the most thorough methods of protecting your crawl space from anything that would threaten to damage it. Our crawl space experts will typically install every part of it for you, so you will not have to worry about setting it up or maintaining it whatsoever.  

  • Sump Pumps and Vapor Barriers   

If your crawl space is flooded, it makes sense for our crawl space experts to first drain all that water away. Ohio Basement Systems’ sump pumps can pump out more than 11,500 gallons of water on a single charge. It is also self-activating and runs on long-lasting batteries. You can rest easy knowing that your crawl space will stay completely dry during even the harshest storms.  

The next step is to install a vapor barrier all around your crawl space. This barrier is made of seven full layers of polyethylene. It is best to install a thick vapor barrier to ensure that nothing can break through it and wreck your crawl space all over again. This barrier will completely block out any moisture that threatens to flood your crawl space. It can also discourage mold and mildew spores from infiltrating as well.   

  • Vent Covers and Dehumidifiers   

In the past, contractors believed that leaving an open vent to the crawl space would help to keep the space well ventilated and dry. Nowadays, crawl space experts know better. Any open vents actually invite even more humidity, moisture, and other issues within the crawl space. The air that circulates within the small space is moist, humid air that slowly causes your floor joists to rot away. Installing our sturdy vent covers over any open vents should solve this problem.  

Dehumidifiers will then work to circulate cleaner air all throughout the crawl space. It can easily diffuse any humidity buildup that manages to break through your vapor barrier or vent cover into a much healthier level for your home. Because your HVAC system is within the crawl space, this means this cleaner air will also circulate throughout the rest of your home as well.  

When looking up various floor joist repair methods online, you might come across a process known as joint sistering. This can be a rather extensive process that ultimately does not solve your over spanned joist problem. 

  • Sistering a Joist 

First, it might help to know what sistering a joist does. Basically, sistering is when you add another joist alongside the old one with nails or other adhesives. The additional joist is meant to bolster the old joist as well as your sagging floor against future issues. Of course, sistering a joist requires just as much precision as an expert will need, so it is not recommended that you sister a joist on your own. 

Sistering joists will help to level your floor for some time. You might even notice the extra beam has stopped your floor from bouncing as well. Unfortunately, sistering works only as a temporary repair, at best, especially if your crawl space still suffers from a moisture problem. Calling the crawl space experts at Ohio Basement Systems is your best bet! 

  • Why It Will Not Work In the Long-Run 

Sistering joists might work to level your floor for a short period of time, but it will not be long before these additional joists face issues of their own, too. This is especially true if your floor joists only started to sag due to a mold, mildew, or pest problem. If you have not gotten rid of these issues before installing a new sister joist, then this merely delays the sagging or bouncing rather than fixes it. The mold and mildew can easily spread to the new joist and affect it as well. 

There is also the matter that sister joists will not block out humidity or other moisture. Sister joists can only do so much for your home before these too start to wear down. It is best for you to set up an appointment with our crawl space experts as soon as possible to prevent this from happening. 

Contact the Crawl Space Experts at Ohio Basement Systems Today  

Your floor should not be uneven, sag, or bounce. Once you start to notice these issues around your home, it can be a sign of much larger damage below. The floor joists should remain leveled and span over a precise amount of space. When your floor joists start to rot or wear down, you need to call the crawl space experts to repair them as soon as you can.  

Contact the crawl space experts at Ohio Basement Systems for a free crawl space inspection and free quotes on all our crawl space solutions today. We serve all throughout Toledo and Cleveland, Ohio, with decades of experience to help your crawl space and joists get back into working order.   

Contact our Crawl Space Experts today!

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