If you’ve recently touched wood in your home and it crumbled from your touch, you may think you have a serious termite problem. However, your issue may not be a pest problem at all. Instead, the cause of the deteriorating wood is likely due to the presence of moisture and fungi growth. This threat can go undetected for years, risking the structural integrity of your home. Left untreated, fungal decay can lead to catastrophic structural failure, potentially costing tens of thousands of dollars in repairs and injuries. Here’s more information about what wood rot is, where it is commonly found, and how you can keep it from damaging your home.
What Causes Wood Rot?
Wood rot occurs by exposure to water for an extended period, repeated moisture exposure, or the wood has not had the opportunity to fully dry, whether because of flooding, a water leak, excess condensation, poor drainage, or lack of protection from rain or snow. Damp conditions encourage the growth of fungi, which then break down the wood.
While wood rot is often associated with aging wood, it can also occur in new wood. Once the fungus takes root, it will eat away at wood of any age.
Signs of Wood Rot
There are different types of wood rot, depending on the fungus species, but essentially there’s wet rot and dry rot.
When wood is consistently damp, certain fungi will thrive leading to wet rot, which can look darker than the surrounding area, as well as soft, spongy, or cracked. You may notice an unusual, earthy odor. Wet rot doesn’t spread but will remain in the moisture-prone area.
Dry rot, on the other hand, can spread to dry wood, making it much more destructive than wet rot. The fungi that cause dry rot may look like small white-, grey-, or rust-colored growths budding on the wood or yellow dust. Wood affected by dry rot can be cracked, warped, brittle, and may break off into cubes. It may even appear like the wood has shrunk.
On painted areas, you may see peeling, bubbling, or flaking paint that may tip you off that there is some type of wood rot beneath. One test to check for wood rot: Poke the area with a flathead screwdriver. If the wood easily sinks in ⅛ to ¼ inches or more, then you likely have wood rot.
How Pests Make Wood Rot Worse
Certain pests can accelerate wood rot in your home by damaging wood and increasing moisture, which creates ideal conditions for fungal growth. Insects such as termites, carpenter ants, and wood-boring beetles’ tunnel through wood, allowing water and humidity to penetrate deeper and weakening the wood’s natural structure. Some pests also carry fungal spores, spreading rot to new areas that were previously unaffected.
This damage creates a cycle where moisture attracts pests, pests worsen the damage, and rot spreads faster. Because much of this activity happens inside walls or floors, rot can go unnoticed until serious structural problems develop.
Where Wood Rot is Commonly Found in Homes
Window
Check the trim, sills sashes, and frames (both inside and outside) for cracks, soft wood, and bubbling paint, which could be signs that wood rot may be developing. You may also find that the window has become drafty, more difficult to open and close, or it may rattle.
Door Frames
Because doors are exposed to the elements, be sure to inspect the frame and note any damp areas or bulges, which may indicate wood rot. The door may also stick or not close properly, or there may be a visible gap between the frame and the wall.
Fascia and Soffits
Since these areas are close to the gutter, wood rot can start to form here primarily when water flow in the gutter is restricted. The trapped water overflows, causing wood rot in these areas of the roof. Look for sagging or uneven soffit panels or gaps where fascia meets the roof or gutters. Also watch for roof leaks, damaged shingles, or water staining near eaves or attic insulation.
Siding
Because wood siding covers a massive part of your home, wood rot here can be very detrimental to your home’s structure. Like most destructive wood rot in your home, it can develop in unseen areas, specifically on the back of the board adjacent to the house. Moisture and fungi that grow here put the structural sheathing at risk and allow water to seep into the wall cavity. This could lead to mold growth, pest infestations, and structural collapse. Keep an eye out for loose or warped siding, swollen edges, and gaps.
Subfloors
This is the place beneath the floor covering and above the floor joists. You will know you have a potential wood-rot problem if the floor squeaks in a specific area or feels bouncy underfoot and gets worse over time. Furniture that is no longer level or cupping or crowning of wood floors may also indicate wood rot. Likewise, tile floors may have numerous cracks, which could indicate wood rot is beneath the surface.
Cabinets Near Plumbing
Another common area for wood rot is where plumbing and wood are in proximity, such as in kitchen and bathroom cabinets. If the plumbing in these areas leaks or produces excessive condensation, the cabinet’s wood may be susceptible to develop wood rot. Check for stains, swelling, bubbling, or peeling laminate or veneer as well as warped panels or doors that no longer function properly.
Structural Beams
Of all the places where wood rot may develop, this one is the most dangerous. It is often challenging to detect wood-rot damage in structural beams because it typically grows in unseen areas. By the time it becomes visible, the beam is severely compromised and, since it is structural, can lead to collapse. A few tip-offs are sagging floors or ceilings, bouncy or uneven floors, doors or windows that are no longer level, or cracks forming in drywall or plaster near beam locations.
Foundation Sill Plate
The foundation sill plate is the first piece of lumber installed in a home’s framing and sits directly on the concrete. This proximity of the wood to the cold, porous concrete may leave it vulnerable to wood rot if it is not adequately protected. The sill plate can also be the hotbed of termite activity. Check for floors that slope, sag, or feel bouncy, walls pulling away from the foundation, or doors or windows that have become misaligned.
Don’t Forget to Check These Areas
Your outdoor structures are also very susceptible to wood rot. Make sure to keep an eye on these elements.
Porches
Porches are common areas for wood rot, which can be exacerbated by consistent moisture, foot traffic, and humidity. It can develop along the ledger board, beneath the floorboards, at the post bases and steps, and at the intersections where the handrail and vertical posts meet.
Decks
As with porches, wood rot may develop heavily in the ledger board area. Joists, beams, and stair railings can also be sites where rotting wood can support fungal growth. Where posts are buried in the ground can be another place where fungi start to grow and cause wood rot.
Fences and Gates
Fences are vulnerable to wood rot, primarily due to ground-contact moisture. The water and fungi at the base of the posts are where the wood rot commonly grows.
Pergolas and Gazebos
Pergolas and gazebos are among the most susceptible to rot. These structures sit fully exposed to the elements. Much of their destruction occurs within center beams, which may house wood rot for years before it becomes noticeable. By the time you spot the fungal decay, the structure will be dangerously unstable.
How to Keep Wood Rot at Bay
Improve Airflow in Moisture-Prone Places
One of the most significant factors that supports fungal growth is moisture. The best way to control wood rot is to deprive it of its essential source. Control moisture levels, and you have a better chance of preventing wood rot from developing in your home. For instance, if your home has a crawlspace or basement, it is ideal to ensure that it is adequately ventilated. Adding a dehumidifier will help control moisture levels in an area prone to high humidity.
Fix Leaks Immediately
Much of the wood rot that develops in a home results from small leaks in the roof, appliances, plumbing, and window and door seals. Fixing the leak and replacing the damaged wood in these areas will help eliminate wood rot.
Seal Wood Surfaces
Sealant helps keep moisture out by acting as a raincoat for the wood in your home. A high-quality sealant prevents water from soaking into the wood where rot begins. Additionally, a sealant with UV protection and fungicidal additives will also further protect the wood in your home from wood rot.
Perform Regular Inspections
Checking your wood or having a professional check your wood for wood rot regularly will help prevent structural damage to your home. Inspecting window seals after heavy rain, ensuring leaves aren’t trapped against the fascia, and checking the crawlspace for signs of moisture are ways to prevent wood rot before it starts. It’s also a good idea to look around the refrigerator, dishwasher, pipes, and the toilet base occasionally.
Frequently Asked Questions
What are some dangers of having wood rot?
In addition to structural collapse, other risks of wood rot include injuries from falling through compromised wood and respiratory issues from inhaling black mold that may be present. It also makes it easy for pests and rodents to enter your home. Another critical risk is that it can reduce your home’s value, making it harder to sell.
Can wood rot spread?
Yes, if it is dry rot, it will spread to other healthy parts of the wood. Stopping the spread as soon as possible is the best way to combat wood rot.
Can I fix wood rot myself?
You can fix wood rot if the damage is cosmetic and minor. If wood rot is affecting structural areas such as floor joists, roof beams, or deck posts, it’s best to call in the experts.
