In certain parts of the country, April is the month of the year that sees the most rain. While this is excellent news for avid gardeners and those hoping to save on watering their yards, the increased wetness has its negative side—namely, its effect on the wood structures in a home. With this in mind, we'll be devoting today's blog post to wood rot, a condition that we mention frequently when discussing common exterior and interior defects found during a home inspection.
Why does wood rot warrant such scrutiny? Because it can be more than a cosmetic issue or a minor annoyance. In its advanced stages, it can compromise the structural integrity of a home and cost homeowners many thousands of dollars in repairs. In its early stages, it can be viewed as a disaster waiting to happen.
So what exactly is wood rot? As with many home-related problems, moisture is the main culprit when wood rot is present. When wood decay spores land on overly moist wood, warm temperatures can spur the growth of fungi that extend into the wood, leaving damaging secretions that soften the material and make it more palatable for the wood-devouring organisms to feast upon. Under ideal conditions (ideal for the fungi, not the homeowner), the fungi will multiply and spread across the wood structure. Such conditions include wood that is repeatedly dampened with excessive moisture without the break it needs to dry out. Types of wood rot include white rot—a string-like, spongy type often affecting hardwoods in the interior of a home; brown rot—a resilient type that presents as crumbly, powdery wood if left unchecked over time; and soft rot, which is more capable of wreaking havoc on the home's exterior.
During a complete foundation-to-roof home inspection, like those performed by a-pro, your inspector will do a visual check for signs of wood rot, paying particular attention to areas that are vulnerable to moisture penetration. Clues that wood rot has taken hold include discolored areas; loose pieces or chunks breaking off; sunken spots; aberrations in the wood's texture such as web-like cracks; a musty, damp smell; and actual fungal growth in cases where the problem has been neglected for some time. Your inspector will indicate when issues—such as obstructed crawlspaces, unstable decks, hidden components, etc.—prevent full access to areas/systems, making a complete evaluation of wood rot and other defects difficult. Also, inspectors often call out freshly painted areas that may be hiding wood rot.
Here are a few of the common wood rot locations that have been reported on by A-Pro Home Inspection over the last 27 years:
Siding: In heavy-precipitation climates, wood siding is highly susceptible to rot due to its constant exposure to the elements. Wood siding that is too close to the soil will be reported on by your home inspector as a condition ripe for wood rot, particularly at the corner boards. Additionally, moisture-holding vegetation that is in contact with the exterior can accelerate the deterioration of wood siding.
Attic: Poor attic ventilation, high humidity, moisture from condensation, and roof leaks can all contribute to roof decking/sheathing decay. While the roof sheathing (plywood or OSB) will likely not be visible to the inspector, the above potentially harmful conditions will be noted in the report, as well as other signs of moisture, such as compressed and moldy insulation, ceiling stains, and a sagging ceiling.
Windows: Wood rot can both cause issues on the exterior and interior of window installations. Along with checking wood framing, trim, and sills, your inspector will see if there are any gaps that may be causing moisture to get inside.
Flooring: Subflooring adjacent to toilets, tubs, and showers are obvious spots for possible wood rot. Additionally, wood flooring on the other side of an exterior door will get a close look, especially if gaps or faulty weather-stripping are discovered during the exterior inspection of the door.
Eaves, Fascia, Soffit: Wood rot is one of the most common defects associated with eaves, fascia, and soffit. Your inspector may discover discolored and softened fascia boards that no longer support the gutter system, or soffited eaves that may be showing rot due to excess moisture saturation from a faulty gutter system, ice dams, inadequate flashing, and other conditions.
Doors: Exterior doors will be inspected for rot, particularly in vulnerable spots such as jambs and wood thresholds.
Decks/Porches: Deck support posts (a common location for wood rot) and other areas will be checked for evidence of decay and structural integrity. Similarly, porch support columns that are in contact with the soil are prone to be affected by wood rot.
Cabinetry: Roof leaks, plumbing leaks, and high humidity can all contribute to the rotting of wood cabinets. Caused by plumbing leaks, the most common issue is wood rot on the bottom of cabinets under kitchen and bathroom sinks.
Other areas in which wood rot occurs include exterior steps, crawlspaces, basements, floor joists, and roof penetrations with substandard, aging, or missing flashing.