What is Dry Rot?What is Dry Rot?

One type of problem that many homeowners do not know much about until it is too late is damaged wood. Most homes have a wooden structure that can be damaged by many things, including wood-eating fungus. This species of fungi can cause damage to the structural integrity of your house.

A building material made in forest product laboratories for newer homes typically has a wood preservative that will kill the fungus that causes damage. But not all homes have this.

If you find rot in your property, there is a good chance that it will need removing, which can be quite costly.

What is Wood Rot in Wood?
Wood rotting is vital to the decomposition process in nature as it turns dead trees into soil nutrition. As the fungus and other natural materials eat the wood, it breaks down and feeds the soil around it. Plant life depends on this process as the richer soil helps plants grow and thrive. In fact, shiitake mushrooms grow on trees with dry rot!

What Causes Dry Rot?

What Causes Dry Rot?
Wood rot is a type of decay started by the combination of fungi (microscopic organisms) and moisture. For fungi to grow, damp wood is necessary, and it must reach a saturation point. Many types of fungi, such as mushrooms and yeast, are beneficial. However, many destructive kinds of wood-eating fungus can be quite damaging.

Different Types of Wood Rot

Brown Rot Fungi
Brown rot (coniophora puteana) is typically called dry rot because the wood surface looks dry. Brown rot fungi will target cellulose and hemicellulose in the structure of the wood. As it starts to destroy the cellulose, the wood shrinks and turns a dark brown color, then breaks into small cube bits. This type of breakdown thrives in temperatures of 65 to 90 degrees Fahrenheit and releases dry rot spores that grow and spread quickly.

White Rot Fungi
White rot (serpula lacrymans) affects wood by making it appear light yellow or white. The wood rot will feel spongy. White rot breaks the lignin of timber. Lignin is another part of the wood structure, and when it gets destroyed, the wood feels spongy.

White rot thrives in temperatures ranging from 65 to 90 degrees Fahrenheit.

Soft Rot Fungi
Soft rot fungi are slower at decomposing wood than white or brown rot fungi. However, this type of fungi thrives in humid conditions and a broader range of temperatures, anywhere from 0 to 110 degrees Fahrenheit. Soft rot fungi will break down the wood's cellulose and leave behind a honeycomb appearance. Fallen trees often have this type of fungal decay, but it can cause rotten wood in a home if conditions are right.

Wet Rot vs. Dry Rot
Dry rot occurs because of a living fungus that begins to eat the wood. Dry rot can develop if humidity between 18 - 30% and poor ventilation merge, providing the perfect fungal growth environment. It also gets infected when mixed with already infected material, e.g., masonry, wood. Dry rot can attack anything from old to newly built homes if dry rot spores and poor ventilation are present. However, it typically only attacks damp timber.

Wet wood rot is a natural decaying process of timber resulting from high moisture levels. The natural decay of timber is necessary for the forest but is not great for your home.

Timber affected by wet rot will feel very damp and spongy. Wet rot treatment depends on placement and severity of the rot. At times, wet rot requires only a simple reapplication of water repellant to stop the rot.

When identifying wet rot, it is essential to find the source of the moisture. The source of moisture, if left untreated, damages wood and can cause more issues. A professional can conduct a rot survey to determine fungal growth and possible damage from decayed wood.

How Common is Dry Rot?
Dry rot fungus is most common in older homes that never got treated for fungi. This type of wood-rotting will occur in any area of a house that is not damp proof or remains damp for long periods. Most often, decaying fungi issues are not detected until a remodeling project exposes them. Some of the common areas for wood decay in a home include:

Use a water-resistant material to prevent rot in your home.

What is Wood Rot in a House?
Wood rot in a house can come in many forms. As the wood begins to rot, the rotting process can cause structural damage. Some of the areas of a home that may be affected by rotting fungi include:

  • Floor joists
  • Ceiling joists
  • Decks
  • Roof decking
  • Support beams and posts
  • Exterior trim
  • Crawl spaces
  • Any other space of the house made of wood

One of the ways to check for infected timbers in your home is to take a thin-bladed knife and peel back a small area of wood. If you notice dried wood with deep cracks running across the grain, you should have it checked out by a professional.

Repair costs for this dry rot damage can be relatively high, which is why it is crucial to understand what wood rot looks like in a home to make repairs as soon as possible and stop wood rot in its tracks. Unfortunately, there are not always visible signs when it comes to identifying wet rot and dry rot.

Does Home Insurance Cover Wood Rot?

How to Tell if Wood is Rotten
There are four main stages in dry rot's life cycle, and each sign of rot will help you identify the problem. The four stages are:

  1. Mycelium Growth
    During this stage, there will be a grey or white cotton wool-like substance growing on the wood. The mycelium can spread quickly through building materials as it searches for new food sources.
  2. The Fruiting Body (Sporophore)
    The pizza-like appearance of the fruiting body makes this stage easily identifiable. The fruiting bodies occur in many sizes and shapes based on the conditions. The fungus spores are typically a deep red, and the outer parts are lighter. The spore dust from these fruiting bodies can be one of the first indications of a possible dry rot issue to a homeowner.
  3. Affected Wood
    The only purpose of dry rot is to remove moisture and create dry wood, so one of the indicators that there is an issue is the wood. The wood will appear shrunken and have a dried-out look. Timber decay causes brittle wood. The wood may also have a warped appearance, and the cell walls will be destroyed.
  4. Dry Rot Smell
    One of the most common ways to identify dry rot problems without physically seeing the problem is a smell. The scent might not mean that you have an issue, but it does indicate a moisture problem. It could lead to a rotting problem depending on how extensive the moisture issue is.

What Does Rotted Wood Look Like?
Dry rot will typically look like a dry block or brick because of how the fungi will consume wood and shed water. The activities of the fungus will create channels inside the wood. You can break off pieces of rotted wood easily.

How Long Does It Take for Wood to Rot?
Dry rot feeds on wood and is a living and growing fungus. If the humidity temperatures and amounts of water are right, this type of wood-rotting can spread quickly through a home as it hunts for more food. For this reason, it is critical to treat dry rot as soon as possible to help prevent wood damage to your home.

Does Rotting Wood Attract Termites?
The primary food source for termites is the cellulose in wood. Additionally, termites are attracted to high moisture content. So, when there are moisture and decaying wood present, it can attract termites to your home as well.

One of the best strategies to prevent both wood rot and termite damage is to make sure that you divert water away from the foundation of your home. Additionally, any moisture issues should be taken care of right away as termites do not like dry wood.

It can be challenging to see the difference between fungi damage and subterranean termites. A termite inspection from a pest control company will determine the cause of your damage. Signs of termite infestation include mud tubes that lead to the ground. Unlike when your home gets infested with bed bugs or other pests, termite infestations can go unnoticed for a long time.

Does Home Insurance Cover Wood Rot?
If you face dry or wet rot issues in your home, contact your insurance company. Your homeowners insurance company can tell you if your insurance policy covers the damage. Many policies have dry rot expressly excluded.

When it comes to covered damages, home and renters insurance typically excludes water damage. The exception is sudden and accidental damage. E.g., they cover burst pipes or leaking roofs after a storm ripped part of your roof off. If the burst pipe or roof resulted in wet rot mold caused by water, the mold damage would get covered by your policy.

However, if dry rot forms from poor maintenance or aging materials, it is excluded from coverage. Your insurance policy will not cover maintenance related damages.

Hope that helps!

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At your service,
Young Alfred