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Dry Rot vs. Wet Rot: What’s the Difference?

Dry Rot vs. Wet Rot

All sorts of things can go wrong when it comes to your home’s water-related appliances. From the plumbing to the downpipes to the rain gutters, the need for a vigilant eye in terms of maintenance and repair is always constant for homeowners. Vigilance for any defectiveness when it comes to the movement of water through your home is not just essential for the efficient movement of said water. It’s also essential for maintaining the structural integrity of your home. This is because any moisture that occurs where it isn’t supposed to can lead to serious damage caused by wet rot and dry rot.

However, wet rot and dry rot are completely different kinds of organisms with completely different biological systems in regards to their nutritional needs and reproductive strategies. They are similar, though, in the fact that they possess the ability to cause a significant amount of damage to your home. In this article, we’ll explain the difference between these two types of organisms, and also explain how to keep an eye out for them, as well as what to do to prevent them from occurring.

Dry Rot

Dry Rot Divine Home Remodeling

We’ll be covering dry rot first because it is a much more serious phenomenon, as it has the potential to cause much more damage to the home than wet rot. Dry rot is the term used to refer to a wood-decaying fungus which has the scientific name Serpula lacrymans. Dry rot feeds exclusively off of timber. Floorboards, ceiling beams, mortar joints, plaster pieces, all of these products are susceptible to infection from dry rot. However, there is one condition that is necessary for dry rot to successfully establish itself in any of these locations, and that condition is moisture. Dry rot gets its name from the fact that it only requires its substrate to have around 20% moisture content in order for the fungus to become established.

The establishment of dry rot can occur in two different ways. The first method that dry rot uses to establish itself is a method that is used by nearly all of the fungal species on Earth, and this method is referred to as ‘spore dispersal’. Mature dry rot individuals are capable of producing literally millions of microscope spores throughout their life cycle. The only thing these spores need to germinate is to land on some kind of timber substrate that has a moisture content of at least 20%. From there, the spores germinate and produce a white, thread-like substance called mycelium. From this point, the dry rot can spread further by either producing more spores, or by employing its second method of dispersal. This second method is what makes dry rot so particularly damaging and worrisome for homeowners.

Utilizing its second method of dispersal, dry rot mycelium can actually grow and travel significant distances to find new sources of nutrition (timber with a moisture content of at least 20%). Specialized threads of mycelium grow out, branching in all directions in search of suitable sources of water and nutrition. The specialized mycelial threads are capable of channeling water, much like little fungal straws, over long distances back to the main body of the fungus, which is typically called the ‘fruiting body’. Some extreme cases of dry rot have been found, where the mycelial threads have actually traveled from one house infested with dry rot, out of the house, under a sidewalk, under a road, across the street, and into another house. This type of spreading is most easily facilitated by the presence of brick or stone walls, which typically have greater moisture contents on their surface, which allows the dry rot to travel over them.

It is important to know how to identify dry rot, as the sooner you are made aware of it, the sooner you can go about getting professional treatment for it. When it comes to fungal decay of timber in the home, time is of the essence for preventing more serious damage from occurring. When inspecting your home, it’s important to keep your eye out for any kind of fungal growth, or anything that seems like fungal growth. If you happen to find fungal growth, look for white growth that has a yellow or lilac tint to it. Dry rot can infect both hardwoods and softwoods, so be sure to give a thorough inspection of all potential sources of infestation. Wood that is infected by dry rot will have deep cracks, which is caused by the fungus sucking all the moisture out of the wood. Finally, any smell that smells distinctly like mushrooms that is occurring in your home could be a sign of dry rot.

Wet Rot:

Wet Rot Divine Home Remodeling

Wet rot is far less capable of spreading than dry rot due to the fact that it requires much greater amounts of moisture to grow, as its name implies. Wet rot can only infest timber that has a moisture content of at least 50%, so if you discover wet rot in your home, it is highly likely that there is a faulty water appliance in your home that is leaking water and soaking your timber. In some ways, wet rot is not as bad as dry rot because it cannot spread as efficiently, but in other ways it is worse than dry rot because it implies that there is significant water leakage occurring in your home.

Wet rot, which is a term that can refer to many different species of fungi, but mostly is reserved for the species Coniophora puteana, reproduces via the production of millions of microscopic spores as well. It has no ability to travel long distances via mycelial growth, however, and is contained to timber that has a significant moisture content.

To identify wet rot, look for timber that has a black fungus or mold-like substance growing on it. Even if you don’t see any black fungus, your timber may be infected with wet rot that has yet to reach the stage in its life cycle that produces black growth. Look for wood that has any kind of discoloration to it, and that feels wet, soft, and/or spongy. It’s also possible that the fungus may have used up all of the available moisture and has dried out. This is still a serious condition, as it means your timber could be structurally compromised, in addition to the fact that all it will take to revive the fungus is a renewed exposure to any moisture. If this has occurred, the infested timber will be cracked and will easily crumble. Finally, your sense of smell can detect the presence of wet rot, which is signaled through a damp, musty scent.


If you find any sign of rot, dry or wet, in your home, it is important to seek professional help right away. Professionals will treat the infestation by identifying any potential source of leakage in your home. They will then assess the amount of damage done to the timber, and will apply a fungicide to any stone or brick surfaces in the home. If the timber has been spared of any serious damage, professionals will apply fungicide to the wood to kill the remaining rot. However, if the wood is beyond salvageable, you will need to replace the infested timber. For this unfortunate scenario, you’ll definitely want to get in touch with us here at Divine Home Remodeling. While this scenario is understandably a pain, it does represent the opportunity for your home to undergo the remodeling work that you’ve been thinking of. Whether you want your home rebuilt exactly how it was prior to infestation, or if you want an entire makeover, we can get the job done. If you’ve already discovered a infestation in your home and need repairs, get in touch with us right away for a free estimate. We look forward to hearing from you!

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