Wood Rot

Bouncy, uneven, or sagging floors are indicators of a much larger problem. Wood rot may be the culprit taking apart your home.

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A home should feel sturdy and comfortable, supporting the family as you go about your business or lounge around during get-togethers. Floors that are uneven, bounce, and sag signify a larger problem within the home. Wood rot is the main culprit behind such problems, though it doesn’t stop at the cosmetic issues. Wood rot impacts the structural integrity of the home as a whole and requires immediate attention. 

Wood rot, sometimes referred to as dry rot, is fast-acting and highly degenerative. Spreading through contact, wood rot can move from one piece of wood to the next with surprising speed. Throughout nature, wood rot is a natural process of decomposition that turns any fallen wood into nutritious soil. This decomposition keeps the cycle going, with the soil it makes providing nutrition for other plants to grow. 

Serpula lacrymans is the fungus responsible for wood rot. Though it’s often referred to as dry rot, it’s only because of the outdated belief that it required conditions devoid of moisture. In more recent years, it was determined that in order to thrive, the fungi actually require a humid climate, and wood rot may be a more correct name. The question is: What causes wood rot in the first place? How do we prevent or fix the issue? Complete Basement Systems serves areas from Denver to Colorado Springs and has the local experts you need if you suspect a wood rot problem. 

wood rot

Do You Have Wood Rot Your Home? 

Out in nature, wood rot is a common process of decomposition that helps turn wood into soil. By its very nature, the fungus that causes wood rot, Serpula lacrymans, is a force to be reckoned with, causing millions of dollars in damage each year. 

This means it’s important to catch the signs early and understand why your home is affected. 

Serpula Lacrymans 

The fungus serpula lacrymans is the sole organism responsible for the start and spread of wood rot. Of course, it requires certain conditions in order to thrive, but without the fungus, rot wouldn’t begin. As a quickly colonizing fungus, it has the ability to spread through large amounts of space in a short amount of time. 

First discovered in 1884, it was soon apparent that the fungus causes a vast amount of damage. Every year, millions of homes are affected by the spread of wood rot, especially since homes usually have the right conditions for it to grow. 


An unavoidable fact of life, moisture is a large factor that contributes to the quick spread of the serpula lacrymans fungus. Of course, every home contains a certain level of moisture, which even humans need to thrive comfortably. The fungus does best in spaces that contain between 30% and 40% moisture. 

Typically, areas that have higher moisture content in the area—but not enough exposure to sunlight to help dry out the spot—will have problems with wood rot. Allowing moisture to continue unchecked will only allow the fungus to grow and spread toward new areas. 

Problem Signs to Watch Out For 

As a homeowner, the most important thing to know is how to spot wood rot effectively. Armed with information, it’s easy to conduct regular checks around areas prone to wood rot. Mark this routine on a calendar or set a notification, but whether it’s done quarterly or yearly, as long as it’s a regular ongoing check, problems can be stopped at the source. 

Here are the most problematic areas to keep an eye on. 


Today’s windows are designed to prevent leaks of air or water into or out of the home. However, nothing is perfect, and small cracks may form through time and use. Areas around and below any windows of the home are continuously exposed to water or moisture, which spreads the fungus quickly. The area below the window is especially exposed to the possibility of being affected by the fungus since there is typically little sunlight. 

Older windows are even more prone to problems, especially those with wooden frames. Time and the elements are likely to wear down any protective barrier the window was built with years ago. To ensure their integrity, always check each window on a scheduled routine. 

Decks Outside 

Though the wood used for building decks and stairs outside is treated to become water-resistant, it cannot guarantee 100% protection. The elements can wear down waterproof qualities, allowing water and moisture to collect inside the wood. Wood rot will spread throughout the entire deck and has the potential of invading the home as well. 

The space with the highest probability of having a wood rot problem is the balustrade of a deck or the stairs. Moisture or water will sit underneath and continue to spread. Remain cognizant of any moving or soft balustrades since those are large indicators of a problem with wood rot infecting the area. 


Pertaining to outside doors, they are one of the most likely places where water can enter the home. Constantly opened or closed, even during rainy days, water has the potential for gathering around the door frame, a perfect place for the moisture to sit and fester. These are not areas exposed to sunlight, which means the moisture content can continue to grow and spread the fungus. 

Wood rot around doors and door frames will cause them not to work right, likely sticking or not fitting inside the door frame. Check for the integrity of the wood surrounding the door and remain aware of any changes in their function to stop a wood rot problem before it grows bigger. 


These are the hotspots of any home for moisture and wood rot to grow and spread. Typically the room with the highest humidity and moisture within the home, it’s the one spot where sunlight is least likely to come through windows, if any are in fact present. It’s the combination of humidity, warmth, and presence of wood that facilitates the growth of the fungus. 

Once the fungus has infected any area of the basement, most likely exposed and unpainted wood, it will spread with alarming speed throughout the entire house. The quick spread of serpula lacrymans fungus can cause potential structural issues such as bouncy floors. It’s important to pay attention to any exposed wood down in a basement for signs of decay or decomposition, as well as any floors above the basement for their structural integrity. 

Wet Rooms 

Kitchens, bathrooms, and laundry rooms are considered wet rooms, or areas of the house with constant water exposure. They are also the areas likely to show a water event in case of a malfunctioning appliance or burst pipe. Apart from the kitchen, and potentially the bathroom, these are areas with the least natural sunlight, aiding in the buildup of humidity. 

Wet rooms need fully functioning vents to help prevent potential issues from forming and spreading throughout the house. Clean the ducts of a home on a set schedule to ensure there is no buildup of moisture that is then spread throughout the home. 


Lastly, roofing is also highly prone to wood rot, though most of the time, it’s damaged roofing that undergoes that problem. When any part of the roofing is damaged, it exposes the wood below it to the elements outside of the home, such as rain or snow. Though there is ample sunlight in the warmer months, constant exposure to moisture will still wear down the structure of the home and help wood rot to form and take hold. 

Fix any roofing issues immediately, especially before any type of rainy or snowy season, to prevent the problem from growing larger. Not even a tarp will be a good solution for the long haul, which means it’s important to contact a professional company for a full inspection.  

Wood Rot


Wood rot has the ability to spread throughout the entire home quickly and almost completely unchecked if not caught early. With crawl spaces and basements as the hot spots of wood rot, flooring is likely to be affected on top of the structural integrity of the home as a whole. 

  • Bouncy Flooring  

Once the structure of the floor, especially hardwood floors, takes on wood rot, floors become bouncy. With every step, the floorboard will give beneath the walker’s feet and then bounce back. Sometimes, it’s possible to bounce with the floor in place, giving it an almost trampoline-like feel. A bouncy floor indicates the structure is not what it used to be, with some of the essential structures impacted by the decay of wood rot. 

Replacing as much of the damaged floor as possible is a first step to fixing the issue, but the structure has also been impacted. Sistering crawl space joists is another essential step toward providing the floorboards above the structure they need to lay flat and stop their bouncing. 

  • Squeaking  

One of the more annoying floorboard problems are squeaking floors. With each step, the damaged floorboard will give way and begin to make a squeaking noise as they grind against each other or the structures supporting them below. A sound coming from the floor with each step indicates the floor and its support underneath are not providing the support they need for someone to walk. 

To solve this problem, aside from contacting a professional, replacing the damaged floor is a good first step toward fixing the problem. It’s important to ensure the joists underneath the floor are fixed or reinforced in some way before any steps are taken to prevent further issues inside the crawl space or the basement of the home. 

Conducting inspections of the home on a scheduled basis is a great way to prevent wood rot issues from spreading but conducting them without knowing what to look for makes the inspection useless. Understanding the look and feel of wood rot is the first important step toward stopping the spread and calling a professional for a thorough assessment. 

  • Structural Change 

Wood rot has a flaky or cracked appearance. When touched, wood infected with rot will crumble upon contact, sometimes becoming lighter if it’s possible to hold. It will cause cracks to form on its own that will spread through the infected wood, effectively splitting it into pieces. 

Depending on how long the wood has been affected by wood rot, it might have a spongy or soft feel. Specifically, it’s easy to press a finger into the wood and see that it will leave a mark or effectively sink into the wood itself, leaving a hole.  

  • Smell and Color 

Wood affected by wood rot will start to change in color and smell, not just in the overall consistency and integrity. Just as it feels soft or crumbling, it will start to have a musty sort of smell indicating the rot has taken hold due to the moisture content in the air. Areas surrounding the wood, such as tight crawl spaces, will start to smell damp even from a further distance.  

The color of the wood will change as well. The areas affected by wood rot will appear darker in color, sometimes with a yellowish tinge. This type of wood needs to be replaced as it is fully affected. Wood with a white film over it means that the rot is still spreading since that is the way it travels from one place to another. Contacting a professional in those instances will help determine whether a replacement needs to be done or if the wood can be treated.   

Floor joists, or the structural support beams, are an integral part of any house, holding up the structure and maintaining its integrity. Rotten floor joists pose problems with the floors and anything above them. Once they are rotted through due to wood rot, it’s important to take the necessary steps to fix the problem. 

  • Sister Beams  

To aid the rotted floor joists, sister beams can be installed to help support the entire structure. A professional can install the sister beams next to the compromised wood along with helping to fix the problem of wood rot. 

The sister beams used to reinforce the rotted floor joists need to be made of treated wood, which is why it’s important to get a professional to help with the process. Though treated wood can also have a problem with wood rot, there is less of a chance it will spread as quickly. 

  • Prevention 

A part of the solution is not only fixing the joists but fixing the problem of wood rot as well. Working alongside a seasoned professional to prevent the start or spread of rot will ensure that any sister beams installed will also maintain their integrity. Wood rot spreads quickly from wood to wood, making prevention that much more important. 

There are different steps a professional can help with, based on the home’s circumstance. Preventive measures may include the use of a dehumidifier or waterproofing measures such as an interior drainage system and a sump pump. These are key aspects of preventing rot from forming in the crawl spaces or any other place within the home. 

Crawl Spaces and Wood Rot 

Much like basements, crawl spaces have the exact same problems. Typically containing lots of exposed wood, crawl spaces are small and likely without any type of sunlight. Moisture and humidity grow in areas such as those exponentially, and then continue spreading throughout the home. 

Check the crawl space and surrounding areas within your home frequently for any signs of wood rot where the wood looks cracked or flaky. Once your crawl space proves to have a problem with wood rot due to the moisture, there are other problems that follow in its wake. 


Once the structure of the crawl space is compromised, the next problem includes insects and rodents. With the integrity of the wood no longer at its peak, creatures understand they have an easier way inside the home to which they are drawn specifically for the warmth and moisture a crawl space provides. 

With these types of creatures living inside the home, there might be a whole host of other problems, such as health issues, aside from the damage they are likely to do on their own. As soon as you suspect the integrity of the crawl space has been compromised, contact a professional, such as those at Complete Basement Systems for a thorough review and a quote for a fix. 

Insulation Problem 

A crawl space provides the rest of the home with much-needed insulation against the elements, such as keeping the home warm during the winter months. If the crawl space has a moisture problem, not only does it facilitate a wood rot problem, but it will also impact the insulation. Wet insulation isn’t as effective, and in reality, it becomes a route for wood rot to travel to other areas of the home. 

Crawl space insulation that has become wet or is not as effective as it used to be, needs immediate removal and replacement. Complete Basement Systems can provide the next best steps to fixing such a problem and determining whether the problem spread throughout the home as well. 

Solutions to a Wood Rot Problem 

Once a crawl space, or any other area of the home, is impacted by wood rot, there are some solutions that need to be taken as quickly as possible. A professional will help determine the next best steps. However, there are some steps most likely to be taken. 


Crawl space encapsulation with a thick and durable vapor barrier is considered the best fix for a home that contains a dirt floor crawl space. The dirt inside of a crawl space helps release moisture into the air no matter how much it’s dried since it cannot be dried past the top couple of inches. Encapsulation helps block off any entrances to water, such as vents or the dirt floor. 

Encapsulation, once completed correctly, helps keep the moisture of the entire crawl space to a minimum, lowering the potential for recurring wood rot problems. This is one of the first steps that need to be completed before any replacement of infected wood should be considered. 

Sistering Floor Joists 

Sistering floor joists involve pairing up healthy wood beams with floor joists that need more support. Though it may not be the only fix (or a full fix), it serves an important function in building up the integrity of the support. 

As much of the infected wood as possible would need to be replaced, but wood rot causes structural issues. This means that there are areas requiring further support to maintain the balance of the home and any structure above the crawl space. 


Wood rot throughout the home, especially if it goes on longer, will impact the floorboards. This means a homeowner is likely to find their floor starting to squeak in certain areas or even feeling bouncy or too soft. 

A professional would need to help repair any damaged flooring and any wood around it. From there, the moisture inside the home would need to be maintained as well as a complete review of potential problem areas on a set schedule. It’s best to catch the problem before it grows larger. 


Having healthy wooden joists is important in your crawl space and other areas in your home. If you have areas of the floor above the crawl space that are sagging, bouncy, and uneven, a more stable solution is needed.  

Instead of light-duty jack posts that can easily fail and not properly support the floors or floor joists, it’s best to invest in a heavier duty crawl space support system. These supports will not rust or corrode, they can help restore the floor back to its original position, and while they protect against settling, they can be adjusted if any settlement or sagging occurs.