Everything You Need to Know about Rotting Wood

Some rotting wood on your property will be visible and obvious, but in other cases the decay will be hidden. This is why it is essential to conduct a thorough, professional inspection of all wood on a yearly basis.

What causes rotting wood? Most wood, unless specifically treated is vulnerable to moisture. An increase in normal moisture levels due to ice dams, melting snow, rain, environmental conditions, etc. increase the risk of wood deterioration and rot.

Fungus, mildew, and organic compounds blossom when moisture is present. Repairing rotting wood cannot be put off as the damage will only spread as time goes on. Then, what may have been an inexpensive repair may turn into a more costly replacement.

Types of rotting wood: One variety of wood looks like spots of decay that appear brown and crumbly, and will break apart into cubes when disturbed. Another variety is yellowish in color, with the decayed wood becoming soft and stringy. If you see surface molds on wood, don’t confuse these with rotting wood. These molds or mildews can be cleaned off the surface of wood and do not break down the fibers or cause any structural damage.

Insects and termites are another cause of rotting wood in certain areas. The insects wear away protective coatings and expose the wood to the elements, a double danger in the world of wood.

Usual areas of damage: When inspecting for rotting wood, pay particular attention to any wood that touches dirt of masonry because water can wick up the wood and cause rotting. Also closely examine joints, which are slower to dry.

The most dangerous situation for rotting wood is when it is hidden behind paint coatings. In this case, you won’t even see the rotting wood, and damage will continue to progress. For this reason, it is essential for a professional to test and inspect all the wood on the property yearly to ensure the substrates are in solid condition. The rotting wood found at this early stage may be repaired in small sections, rather than require a more expensive, full replacement.

Once rotting wood is confirmed, the scope of repairs depends on the amount of time the wood has been exposed, the extent of the damage, and the threat to the structure. Professionals use tools to expertly inspect the most common areas for first signs of rotting wood, whether visible or hidden:

Soffits, Fascia & Trim Siding Window Sills & Frames
Doorway Thresholds & Frames Columns Beams & Joints
Decks & Fences


Preventing rotting wood is just as important as repairing it. The key to deterrence is to control the wood’s exposure to moisture by providing adequate ventilation and water drainage and maintaining its protective coating cycle.