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High Humidity

High humidity can cause many issues in a property, but it is also a problem sign for many deeper issues within a home. This makes it a problem you should not ignore!

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Of all the things that can be at work in your property, humidity is one of the most insidious and potentially damaging to every aspect of the structure, the furnishings, and even the health and well-being of anyone who lives in it. High relative humidity takes root for a number of reasons and is classed as a warning sign for a number of different issues, both structural and cosmetic. Of course, as well as being a symptom of structural damage, humidity can contribute to it. 

The generally humid summers across the state will make homes in Missouri more susceptible to issues with moisture and water damage. This is especially the case for properties that have unsealed or non-waterproofed crawl spaces. Learning to spot the early signs of humidity and dampness is incredibly important for homeowners who want to prevent avoidable issues within their homes.


What Can Cause High Relative Humidity? 

High relative humidity is really caused by only one thing: too much moisture in an environment. As this moisture evaporates into the air, the level of relative humidity increases until, eventually, the air cannot hold any more moisture. When this happens outside, the result tends to be rain, but this is not possible inside, of course. As such, condensation is likely to form on cool surfaces. 

Of course, there are many things that can cause humidity inside your home. The most common are: 

Poor Drainage Systems 

One of the leading causes of high humidity in any property is poor interior and exterior drainage systems. If your property lacks adequate drainage options, or your drainage systems are damaged, the likelihood of dampness, water damage, and generally high levels of humidity within your property increases exponentially. Most homes are designed to have adequate drainage for their location and the climate. So, unless a property is very old or the climate has recently shifted to become wetter, the most likely cause of this issue is damage to your drainage systems. 

The most common causes of damage or inefficient drainage are blockage, sediment buildup, or (in the case of appliances like a sump pump) mechanical failure or breakdown. Depending on the severity of these issues, you could even see full-scale flooding in your crawl space.  

Internal Leaks 

Another cause of dampness and humidity in a property is an internal leak or a series of internal leaks. These can be incredibly damaging, especially when the leaks are small and prolonged. A consistent, low-level leak will do far more to increase the relative humidity in your home to dangerous levels very quickly. This can lead to many different issues, but the most common and potentially damaging are wood rot and mold formation. 

Internal leaks are those that come from your plumbing system, but this can mean many things. First and foremost, you could have a leak in your pipes, but there is also a strong likelihood that appliances and fittings that are attached to your pipes are the cause. Weak joining points between your pipes and water heater or sink, for example, can cause a lot of issues. 

External Leaks 

External leaks are leaks that let water into your home from outside. These leaks can be incredibly small or very large and noticeable. Either way, they can cause huge amounts of damage to your home, both directly and as a result of water damage. Perhaps more worryingly, external leaks tend to be a sign of structural damage to your property. 

External leaks can take a number of different forms, but the most common are leaks caused by cracks in a property’s foundation, in the walls of a property, or due to damage in your windows. 


Seepage is an unusual but fairly common occurrence in homes with concrete foundations and crawl space walls. Concrete is incredibly porous and will absorb water, especially if the ground around the property is heavily saturated. Over time, this water can seep through the concrete entirely and cause the relative humidity in a property to rise. 

Seepage is not necessarily a result of structural damage, and neither is it overly likely to cause structural damage on its own. This makes it a little tricky to address. 

Usually, when there is a sharp increase in relative humidity, the cause will either be one large source of water (which should be easy to find) or a buildup of many different smaller leaks. As such, it is important that you learn to recognize the signs of high humidity. 

Problem Signs of High Humidity 

If you think that your property may have issues with high levels of humidity, there are a few warning signs you can look out for. It is important to remember that many of these may also be warning signs for underlying issues. As such, you should contact a professional as quickly as possible when you see them. 

Wet Walls 

Condensation is caused when there is too much moisture in the air. When humid air comes into contact with a cool surface, condensation will form. 

Condensation of any kind should be a cause for concern unless there is an immediate and obvious cause. Wet walls, however, are by far the most pressing sign of humidity and dampness at work. By the time condensation has started to form on your property’s walls or flooring, you can be certain the humidity in your home has reached a breaking point. 

If you see beading water on your walls, this is an incredibly serious and advanced sign that you should never ignore. 

Bad Odors 

A strong, musty odor that spreads throughout your property without an obvious source is a big red flag for humidity issues or crawl space flooding and dampness. This can simply be the smell of stagnant water, but there are other, more serious possibilities. Mold, rot, and pest infestation can all add certain edges to the smell of dampness. If a deep clean doesn’t shift the smell and it won’t disperse no matter how you try to air your home out, the issue is most likely persistent humidity and dampness. 

If the odor is particularly pungent, you should search your crawl space to make sure that there is not a dead animal somewhere in the space. This is unfortunately common in properties that have uncovered or loose crawl space vents or doors. 

Mold and Rot 

If you see mold spreading through areas of your home that have no water outlets of any kind, this is a very strong sign that you have high levels of humidity in your home. You will be able to recognize mold and mildew by the way that they form and spread across surfaces like wood, wallpaper, tiles, and even textiles. There are even some kinds of mold that are most at home inside HVAC systems (which can spread the smells very quickly). 

Increased Energy Bills 

If your energy bills start to rise for seemingly no reason, you should investigate the levels of humidity in your home. There are many things that can affect your energy usage, but if you have not changed your habits and the increase can’t be accounted for by seasonal changes, humidity is a likely cause. You see, humid air is far harder to heat and cool than arid air, so your HVAC systems will be forced to work harder to give you the same results. This will increase energy usage and your bills. 

Standing Water 

Pools of standing water around your home or in your crawl space are a very strong sign of issues with dampness and humidity in your home. In fact, they will actively create humidity in your property unless they are drained. Standing water is also a sign of structural damage and internal leaks. This means there could be many more worrying issues at work in your home. 

The placement and amount of water can help you to understand what the overall source is. For example, if most of the water is found in the corners between your walls and floors, it is more likely to be seepage or a leaking pipe. If the water is inconsistently spread through your crawl space, however, foundation issues might be at work. 

These are just some of the most common problem signs of humidity and dampness in a property. There are many others to look out for. However, if you see one of two of these at the same time, you should contact a professional immediately. Do not try to address the problem alone, as you are very likely to end up misdiagnosing the underlying cause or long-installing an unsuitable solution. This could lead to the real problem going unchecked, or even cause more damage to your home. 

High Humidity


If you have noticed damage to your wallpaper, whether it be bubbling, peeling, or staining, it is most likely that humidity and dampness are the root causes. These are primarily cosmetic issues, but if you see small black flecks on your wallpaper, this is a more serious issue. It’s a sign of mold. 

Leaks or Seepage 

Dampness is a prerequisite for any kind of mold and mildew formation. This is why kitchens and bathrooms are the rooms in any property that are most prone to mold formation. If you have an unsealed crawl space or damage to the structure of your property, however, the relative humidity in your home can rise to dangerous levels. This can lead to many different issues that range from cosmetic in nature to structurally damaging. 

Sources of moisture can be broken up into internal and external. Internal sources are generally those that are connected to your home’s plumbing system in some way. However, they can also come from drainage systems like your sump pump. External sources are those that allow moisture into your crawl space from the outside like foundation cracks or bowing walls. 

Mold Formation 

However moisture gets into your property, mold and mildew formation are sure to form once the levels of humidity have risen high enough. This can cause a number of issues for you and your property. The most noticeable side effects are the appearance of discolored spots and the spread of a musty odor. However, there are different kinds of mold that can have different effects. 

Some forms of mold are most likely to settle on wood, for example, while others may be best suited to spreading inside HVAC ducts. Once mold takes root, however, the process of removing it remains much the same no matter what kind of mold it is. The formations will be treated and removed, but the underlying cause of moisture will have to be dealt with as well! 

Mold can be a plague on a property once it has taken root, but it is not always dangerous. Some forms are fairly benign, if unsightly and unpleasant, but others can be actively damaging to your home and health. 

Property Damage 

Certain species of mold and mildew are more dangerous to the structure of a property than others. The species that are most worrying in terms of the stability of your property are those that form on wood, drywall, and plaster. These kinds of mold are more likely to cause the structure of your property to become weaker and less stable. 

In fact, certain species of mold go hand in hand with wood rot and will eat away at any surface that it grows on. This will lead to the wood or drywall in question getting soft, weak, or even bendy. This can cause walls to bow and floors to sag. In fact, if mold takes root in drywall, it could crumble entirely and leave you with a heavy repair bill to deal with. 

Health Issues 

As well as the obvious structural issues, mold and mildew formation can bring serious repercussions for your health and well-being. For example, they can cause skin irritation, dizziness, and even headaches in relatively healthy people, but this is not the worst of it. 

For people who have underlying health conditions, the side effects of mold formations in a home can be far more serious. If you have underlying respiratory problems, for example, or a skin condition like eczema, there are certain species of mold that could exacerbate your condition. This can lead to side effects of varying severity, but for people who have serious lung conditions, it could result in hospitalization. 

Of course, the best approach is to prevent high humidity and dampness from taking root in the first place. In order to do this, there are a number of things that you can do (or have a professional do) to protect your property. 

Ensure Proper Drainage 

Every property has some sort of drainage system built in. From the roof gutters and downspouts to foundation drainage, most properties have basic systems in place to divert water. Of course, that doesn’t mean that these systems are adequate. In wet and humid areas like Missouri, a property should have a variety of moisture management systems in place. 

Having interior and exterior drainage systems will be important if you are to keep the humidity levels inside your property consistently low. For properties that have a crawl space, this means considering the health and condition of your perimeter drains and sump pump. Scheduling regular cleaning and maintenance will help to keep your existing systems in peak condition. 

Professional Waterproofing 

If you are keeping your existing drainage systems in optimal condition, but you are still seeing signs of dampness and humidity in your property, it may be time to consider waterproofing services. Professional waterproofing services can provide you with a far better result than DIY waterproofing, as well as a more durable solution to your issues with dampness. 

Fully encapsulating your property’s crawl space is one of the best things that you can do to prevent humidity and dampness from working on your home. However, it will also provide you with a range of benefits. An encapsulated crawl space, for example, is one with a more consistent climate in terms of temperature. This will lower your average energy costs considerably by making it easier to keep your home at the optimum temperature. 

Why Should You Worry About Humidity? 

We understand that humidity might not seem like the most worrying issue to have in your home, but you should be concerned if you have consistently high levels of humidity. Humidity and dampness can cause many different problems for your property, some of which have more long-term implications than others. The most common side effects of prolonged, high-level humidity are: 

Mold and Mildew Formation 

Mold and mildew are almost guaranteed to form in damp and humid environments. This is why even healthy homes can find issues with mold in their bathrooms and kitchen if they are poorly ventilated. Depending on the species of mold in question, this can cause serious repercussions for both your health and your home. For example, some species of mold will form on and eat away at wooden support joists and beams. This will have serious, long-term repercussions. 

Of course, there are also many species of mold that can be damaging to your health and well-being. Black mold in particular can cause headaches, dizziness, skin irritation, and even respiratory problems. 

Wood Rot 

Wood rot is often co-occurring with mold formation. In fact, certain species of mold thrive best on rotting wood. However, rotting wood will cause issues in your home even when there is no mold present. The most common side effect, apart from a horrible smell, will be sagging floors and bowing walls. As wood rots, it loses its structural integrity and will become soft. In serious cases, this can lead to the walls or floors that are affected collapsing. 

Pest Infestation 

Crawl spaces that are humid and filled with mold are far more likely to attract pests than crawl spaces that are dry and free from mold or wood rot. The precise nature of the pests that might be attracted can vary, but the most common are cockroaches, spiders, and rodents. 

Pests of any kind are undesirable, but cockroaches and rodents are particularly unhygienic and damaging to your home. 

In homes that have suffered from high humidity and dampness for a long time, these issues will usually combine to create a pretty unpleasant smell (which is one of the strongest problem signs to look for). As such, learning to recognize and deal with high humidity quickly is a must 

Crawl Space Repair with Foundation Recovery Systems 

Realizing that the humidity levels in your property have reached dangerous levels is always concerning, but there really is no need to panic. Professional advice can help you to identify the root cause of dampness and formulate a viable solution very quickly. 

Foundation Recovery Systems has been a prominent provider of crawl space and foundation repair services in Kansas City, Moberly, St. Louis, and Springfield, MO, since 1992. We know what it takes to make a home secure once more. The whole process starts by scheduling a free inspection so that our team can get an idea of just what your home needs. These appointments are free, come without obligation, and include a written estimate for our suggested services and repairs. 

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2401 SE Creekview Dr.
Ankeny, IA 50021

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Kansas City, MO 64153
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211 SE State Route 150
Lee's Summit, MO 64082
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Moberly Location

1401 US-24
Moberly, MO 65270
(660) 202-8662

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1820 N Barnes Ave
Springfield, MO 65803
(417) 612-8286
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1625 Larkin Williams rd.
Fenton, MO 63026
(314) 207-9995