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Crew installing dehumidifier in crawl space

Loose Crawl Space Doors

Loose or ill-fitting crawl space doors are not just inconvenient, they directly contribute to the deterioration of your home’s interior climate!

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Covering crawl space doors and vents is an incredibly important step in protecting any home, but especially for those in places like Minneapolis, MN, where the falls can be very wet and the spring brings huge amounts of water as a result of thawing snow and frost. However, most people do not realize that installing a poorly fitting or loose crawl space door or vent can be worse than leaving the vent or access hatch uncovered. This has a lot to do with airflow and the damage that excessive humidity and dampness can cause. 

Open vent

Furthermore, while it may be separate, your property’s crawl space has a huge impact on the overall health of your home and the interior climate that you enjoy. Any issues in your crawl space caused by a loose or ill-fitting crawl space door will eventually impact your property as a whole. This can impact your health, your energy usage, and even your décor. 

Here’s Why We Need Crawl Space Doors and Vent Covers 

Crawl space doors and vents are common in homes across Sioux Falls, SD, for one main reason. Between the 1950s and 1990s homes were constructed with crawl space vents in place as a matter of best practice because they were believed to reduce humidity and prevent dampness by increasing airflow around your property. Of course, crawl space vents and access hatches do increase airflow, however, this creates a new problem. 

The stack effect is a process that increases airflow and creates moving channels of air from the bottom of a property to the top. The problem is that this airflow has been recognized as harmful to a property in several ways. First and foremost, the increased airflow from outside drastically cuts heat or cold retention, lowers energy efficiency, and makes the climate in your home unstable. Secondly, it allows airborne allergens and bacteria to enter your home from the outside. 

This can have many different implications for the structure of your property, your personal belongings and furnishings, and even your health and wellbeing. As such, crawl space doors and vent covers are an excellent solution for your property when you don’t want to undertake serious structural work to remove the vents and doors overall, or when you want to maintain an external access point for your crawl space. 

What Can Cause Loose Crawl Space Doors? 

The precise causes of your loose crawl space doors can vary and will depend on the age of your crawl space doors, the material the doors or covers are made from, and the state of your home as a whole. Nonetheless, some causes are more common than most. These include: 

Poor Design or Planning 

The most common cause of issues in a crawl space vent or door is poor design or poor planning. If the materials used in making the vent cover or door itself are faulty, weak, or prone to cracking, this will inevitably lead to damage and allow water into your home. Likewise, if the materials are incredibly heat-reactive they may swell and shrink as the seasons change and could warp over time, which may lead to them becoming loose. 

Secondly, if the person who installed your vent covers did not measure the size of the vent or door properly, the vent cover could well be the wrong size. Even if it looks like it is the right size, a millimeter of difference can have a huge impact on the effectiveness of the vent cover or door. 

Worn Sealant 

All crawl space access hatches and vents require spaces to be cut into the foundation walls of your property. As such, the seams between the vents and the foundation wall need to be sealed properly to prevent dampness from infiltrating your crawl space through these small spaces. The seams are generally sealed at construction, of course, but over time the sealant can wear away. 

When this happens, a vent cover can appear to be loose when in fact it is the vent itself. However, this can also lead to the vent door being loose if the sealant that is wearing away is also attached to the rim of the vent door itself. 

Structural Damage 

Structural damage will let water into your crawl space no matter where it is found. Cracks and concrete deformation are obvious sources of damage, but what many people do not realize is that issues like foundation subsidence and settlement that can cause sticking windows and doors may also damage your crawl space vents. 

You see, as the walls lean, bow, or shift position, your property’s crawl space vents can become deformed just like the frames of your doors and windows. This will lead to previously snug vent covers and doors becoming loose and no longer fitting the vents, thereby letting in water. 


Every product has a natural life span after which it becomes less effective and more prone to damage. Crawl space vent covers and doors are no different at all. Older covers in particular are prone to deterioration because of the materials that they were made of. 

Previously, vent covers were made of materials like treated wood. This means that they will deteriorate and even start to rot over time. Modern covers are made from materials like PVC, however, which are weather and temperature resistant. 

Whatever the causes of your loose or ill-fitting crawl space doors and vents, there are several warning signs that you should be aware of. Being able to spot these issues early will help you to rectify the issue before serious and avoidable issues take root in your home. 

Problem Signs to Look For 

These problem signs can be indicative of many different issues in your property’s crawl space. This is why it is important to include a professional where possible. These warning signs may not mean much to you, but an expert will be able to read them like a book! 

Wet Rot 

Wet rot looks different depending on where it is found. Insulation will likely start to droop or fall away from the ceiling or walls of your crawl space in strips and will often become discolored. The most likely form of discoloration is yellowing. Wood, however, will take on a white-ish sheen and be soft or crumbly when touched. This may lead to sagging floors. 


Mold in your crawl space is a very general sign that something has gone wrong and caused the humidity levels in the space to increase sufficiently to harbor mold and mildew. However, this is a very general problem sign, so it is best to get a professional involved quickly to ensure that you get the right solution for you. 

Gaps in Sealant 

You should check the sealant around your crawl space vents as a part of your seasonal maintenance. If the sealant looks worn, damaged, or there are gaps in it, you should act quickly. This will let water and moisture into your property and cause a lot of trouble in a very short period. 

Bad Smells 

Your crawl space may not be the most pleasant part of your home, but it should not have a strong or unpleasant smell. If your crawl space smells bad or musty, there are several possible causes from pest infestation and mold formation to general dampness and wet rot. You could be forgiven for thinking that this is not a big issue, but this smell will soon pervade the rest of your home. If you want to get rid of it, you have to act quickly. 

Visibly Loose Covers 

If your crawl space doors or vent cover are visibly loose, hang from the vent or access hatch, or are visibly deformed you should have them replaced as soon as possible. This is the strongest sign that there is a problem with your vent covers or doors and will contribute to a generally damp or unhealthy environment in your home. 

Pest Infestation 

If you notice pests in your home and cannot find their nest, it is very likely that they are in either your crawl space or your attic. Signs of pest infestation include shed skins, droppings, signs of chewing, and visible sightings of pests. Some pests can get into your home through very small spaces and crevices, but others will require a bigger entrance area, like a loose crawl space door. 

Spreading Cracks 

Some cracks are normal in any property. Hairline cracks are those that are stable and too small to fit a credit card into and can be caused during the natural relaxation of a property. Spreading cracks, by contrast, are those that are actively growing in length, depth, or width, and they are a sign that your property is struggling to cope with intense pressure of some kind. If your crawl space doors are also loose, this could be the result of structural damage deforming the wall around the vents. 

Pooling Water 

If you find pooling water in your crawl space, this is a huge red flag. It can either be the result of structural damage, damage to your property’s foundation, or damage to the internal systems of your home. Plumbing damage or leaks, for example, will cause water to pool in your crawl space over time. Unless the water is pooling directly under your property’s crawl space vents, however, it is unlikely that a loose cover or door is the cause of the water. 

If you see these problem signs in your home, you should contact a professional as quickly as possible. Letting a professional deal with these issues before they snowball into more serious issues, like a sagging floor or bowing walls, will save you huge amounts of time and money in the long run. 

 Moldy wet rotten

Loose Crawl Space Doors


If your crawl space has already been waterproofed and encapsulated, there should be no reason why it is consistently damp or wet. The most likely causes of this are damage to your property’s structure or a loose or damaged crawl space door or vent cover. 

Structural Damage 

If water is making it past your property’s waterproofing measures, the most likely cause is damage of some kind. This can be damage to your property itself, like foundation settlement or subsidence, which are caused by problem foundation soils. Any damage that sees cracks spreading through the full width of a surface to the exterior of the property will let water seep into your crawl space. Of course, because of your waterproofing measures, this water will be trapped inside your property and become stagnant. 

Alternatively, internal damage and issues like plumbing leaks and appliance breakdown can very easily lead to water dripping into and collecting in your crawl space. When this happens, your crawl space will become damp and be more likely to harbor mold, mildew, and fungal growths. This will cause a lot of secondary and tertiary issues in your property. 

Loose Crawl Space Doors or Vent Covers 

If there is no damage to the structure of your property or your plumbing systems, the cause of your property’s dampness and moisture problems likely lies in your crawl space vent covers. If your crawl space vent covers and doors, for example, are becoming damaged as a result of exposure to the elements, water may start to seep into your home. 

Likewise, if the sealant around your vent covers becomes worn, or the vent covers and doors themselves are poorly fitted to the access points or vents, water and pests will be able to get into your crawl space over time. Thankfully this issue is fairly easy to rectify. You just need to dehumidify your crawl space and reseal your crawl space vents and doors with covers that fit well. This will prevent the recurrence of dampness in the future. 

Loose crawl space doors or ill-fitting crawl space vents can cause a huge amount of damage to your crawl space and, of course, your property as a whole. This may seem surprising, but you must remember that your crawl space is still a part of your home as a whole. 

Crawl Space Damage 

Loose crawl space doors primarily cause the environment in your property to shift and become less healthy. This deterioration is caused by dampness and moisture. Persistent dampness and humidity in your property’s crawl space are incredibly damaging in several ways. From mold and mildew formation to wet rot, dampness creates situations that are unsafe as well as unhygienic. Some species of mold can be damaging to your health and wellbeing. Black mold, for example, can cause skin irritation, rashes, headaches, dizziness, and respiratory problems. This will, of course, most seriously impact people who already have health problems. 

Wet rot, by contrast, is most likely to impact your crawl space insulation and exposed wooden beams and joists, the structure of your home, in short, rather than your personal health and wellbeing. This will cause your property’s energy efficiency to drop and attract pests, many of which will nest in rotting insulation, and could even damage your property’s flooring. Wet rot in wood makes it lose its structural integrity and can cause flooring supported by damaged joists to sag, warp, or even collapse. Unfortunately, there is no way to restore the wood to its original condition after it has started to rot. 

Issues for the Whole Property 

When your crawl space is suffering from dampness and humidity, the causes may be localized, but the effects will be felt throughout your whole home very quickly. This is partly because of the stack effect, which increases airflow and spreads airborne allergens throughout a property very quickly. As such, when you have issues with dampness, humidity, and mold formation in your crawl space, this will quickly affect your whole home. Certain species of mold could even spread through your property’s HVAC vents, making them hard to get rid of. 

This can cause many issues, including bad smells, fluctuating temperatures, the spread of mold into your main home, or even an increase in your property’s energy usage and bills. This decrease in energy efficiency occurs because humid air is far more difficult for HVAC systems to process than arid air. This will lead to them working harder to produce the same results and could increase wear and tear on your system, leading to avoidable breakdowns and damage. Furthermore, your interior climate will be unstable when relative humidity is high. 

We feel that it is important to waterproof your crawl space no matter what state your home is in, after all, it is one of the most exposed parts of your home. However, it is most important that you waterproof your crawl space after large repairs. 

Avoid DIY! 

Whenever you decide to waterproof and encapsulate your crawl space, whether you are doing this for the first time or upgrading existing waterproofing measures, we urge you not to try Do-It-Yourself. We understand that it is tempting to undertake this work alone to save some time and money, but this often backfires hugely when homeowners without experience or training try to do it alone. 

The problems with DIY are many, but the most obvious and pressing issues are the availability of high-quality, professional standard products and tools, and the likelihood of causing extra damage to your home is huge. If you install a product incorrectly, or you fail to notice a point of damage in your crawl space you could end up dealing with huge amounts of damage at a later date. 

The Benefits of Professional Waterproofing 

Professional waterproofing, however, has many benefits for all spaces and properties. These include, but are not limited to, a decrease in relative humidity throughout your property, an increase in heat retention, a lowering in energy usage, and reduced energy bills. The increased energy efficiency that your home experiences is the result of lowered humidity; humid air is harder to process than arid air, after all, and it makes your HVAC system work harder. 

As well as the removal of moisture and humidity, waterproofing will contribute to a more stable and healthy environment on your property. By removing the likelihood of mold formation and minimizing the intake of allergens from outside (which often infiltrate non-encapsulated crawl spaces because of the stack effect), waterproofing can prevent health issues from forming and pre-existing health conditions from being exacerbated.  

Call Innovative Basement Authority for Crawl Space Repairs 

If you think that your crawl space vent covers or doors may be loose, cracked, or damaged, please do not delay. We know this may not seem like a huge issue, but as you now know it can cause a lot of problems. What’s more, this issue is very easy and cheap to fix when caught early. Making a call at the right time could save you hundreds of dollars in the long run. 

You can even book a free inspection appointment online or by phone. Our team will help you to schedule this appointment for a time and date that suits you, and when our inspectors attend your property, they will make sure to talk you through their findings before providing you with a written estimate for all associated costs. Homeowners in Fargo, ND, Minneapolis, MN, Rush City, MN, and Sioux Falls, SD will have everything they need to make an informed decision. 

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Innovative Basement Authority Service Map

We service Minnesota, North Dakota, South Dakota and Eastern Montana for basement waterproofing and crawl space repair.

Fargo, ND

1330 41st St. N
Fargo, ND 58102

Minneapolis, MN

6265 Carmen Ave.
Inver Grove Heights, MN 55076

Rush City, MN

1325 S Frandsen Ave
Rush City, MN 55069

Sioux Falls, SD

101 S. Reid Street, Suite 307
Sioux Falls, SD 57103