Dry rot vs wet rot: Differences, Causes, And Treatments

Wet and dry rot are two types of fungi that can damage your home’s wood and other building materials.

Wet rot requires around 50% or more moisture levels to grow, while dry rot is more aggressive and can grow in lower moisture levels of around 20% to 30%.

Dry rot is caused by a single type of fungus, Serpula Lacrymans, and is more dangerous as it can spread throughout a building and cause significant damage.

Both types of rot can be caused by faulty plumbing or penetrating dampness from damaged roofing and guttering.

Early detection and treatment of these types of rot are important to prevent structural damage to your property.

The main differences between dry rot and wet rot

Both types of rot may be caused by fungal decay in wood timbers, but the main difference is the moisture level required for them to thrive.

Wet rot is a bit of a moisture hog, needing lots of water to grow, while dry rot can spread like wildfire, even in areas that aren’t wet.

This means that wet rot often stays in specific, damp spots, but dry rot is a much bigger threat since it can spread throughout your home.

Different types of fungi also cause wet rot and dry rot. A host of fungi can trigger wet rot, but dry rot is only caused by one type of fungus. This is why wet rot is more common, easier to contract, and treat.

On the other hand, dry rot is a sneakier culprit, harder to spot, more difficult to get rid of, and requires a more specialized treatment.

So, the bottom line is this: What is worse wet or dry rot? Wet rot is the more manageable of the two, but dry rot is the real danger. Keep an eye out for both, and don’t let them take over your home!

What is dry rot?

Dry rot is a major issue for any building and can spread rapidly, causing extensive damage along the way. Unfortunately, it often starts from simple things like poor airflow, rising dampness, or leaks and can go undetected for a long time while it quietly causes harm behind walls and under floors.

With just a 20% moisture content, dry rot is activated and becomes even more dangerous as it generates its own moisture while breaking down the timber. If you think you have dry rot, it’s essential to bring in a professional surveyor to assess the situation immediately.

The earlier it’s identified, the better. However, it may take a thorough investigation to determine the extent of the damage.

Dry rot, also known as brown rot, is the most severe form of fungal decay and attacks the cellulose in the wood.

Despite its name, dry rot is not always dry as it thrives in dark and humid areas, drawing moisture from the wood and turning it dark brown and brittle.

Before you know it, dry rot has infected more wood and can grow over a meter in just a few months. Don’t let dry rot take hold in your building; always be on the lookout for any signs, and call in the experts if you suspect anything.

How to identify dry rot?

Dry rot is a sneaky and damaging fungus that can wreak havoc on your house if not caught in time. It’s crucial to be aware of the signs so you can identify them before it becomes a major issue. Dry rot infects timber and causes it to shrink, crack, and become soft and spongy.

The surface may still look fine, but the rot is hiding underneath. It can produce fruiting bodies that look like mushrooms and release red spore dust when it’s well established.

To know if you have dry rot, you may notice the timber shrinking and appearing dry, brittle, and crumbly.

It could also look darker than usual and have split or cracked into small cubes. If you have flooring, it might feel bouncy or creaky and even start to drop away from the skirting boards. If you spot dry rot in wood flooring, your masonry and brickwork are likely in trouble too.

Dry rot is easy to differentiate from wet rot. Dry rot has a distinct appearance, with deep cracking and a dry, severely cracked look that’s grey or brown. It can also give off a musty, mushroom-like smell due to the fruiting bodies it produces.

However, these signs may be harder to spot if the wooden surfaces are painted. But don’t worry; you can still look for the yellowish tint of the interior fibers and the tell-tale cracking.

Where dry rot grow and how to prevent it

Dry rot can be a major headache for homeowners, but don’t panic just yet! Let’s take a closer look at where this sneaky fungus likes to lurk.

Any wooden surface in your home exposed to dampness, from the roof to the ground floor, is a prime target for dry rot. And it doesn’t matter if your home is old or new – dry rot can strike anywhere.

So, what causes dry rot? Moisture is the key factor – it’s like a green light for dry rot to multiply. Leaky roofs, faulty gutters and masonry, and plumbing leaks can all lead to dry rot. This fungus loves to hang out on poorly ventilated roofs, underfloor areas, and walls.

If you have dry rot in your house, it’s important to take action immediately. The symptoms of dry rot are quite noticeable once you know what to look for.

You may see red dust from spreading pieces with a fruiting body nearby or white mycelium that appears like cotton candy with brittle strands mixed in. And if you observe a grayish-white “skin” with yellow or light purple spots, it indicates that dry rot has taken over.

So, to keep dry rot at bay, keep your home well-ventilated and watch out for any moisture issues. Trust us, and it’s much easier to nip it in the bud than to deal with an advanced infestation.

How to Effectively Treat Dry Rot

Dry rot is a destructive fungus that can cause a lot of harm to your property if not addressed. To prevent further damage, it’s crucial to locate the source of the moisture and eliminate it.

We’ll guide you through treating dry rot in your house and removing the fungus.

Step 1: Figure out where the water is coming from

To treat dry rot, the first step is to find and get rid of the source of moisture. This could mean fixing broken or overflowing gutters, plumbing problems inside the house, or fixing damaged render.

Step 2: Figure out how bad the outbreak is.

Once the source of moisture is gone, it is important to figure out how bad the outbreak was and how much damage it did. A trained person will look at the situation and determine what needs to be taken away. This could mean taking out the floors, walls, or decking boards.

Step 3: Take out the infected wood

To stop dry rot from spreading, infected wood must be taken out. The infected wood should be cut back at least 500 mm past the last sign of fungal growth or hyphae strands. Mycelium, hyphae, and fruiting bodies that can be seen should also be taken away.

Step 4: Treating the rest of the wood

Replace the damaged wood with already treated wood, and use a dry rot treatment fluid on the rest of the wood. These special fungicides stop new infestations from happening, and a wood preservative like Ronseal can stop the rot from happening again.

Step 5: Fortifying Timbers

Wood filler and wet rot wood hardener can strengthen timbers, especially around doors and windows, if the damage is not too bad.

Step 6: Clean and sanitize the brickwork

Before putting the wall, floor, and ceiling fabric back in place, it is important to deal with all of the rot. The brickwork and masonry will also need to be cleaned with a treatment for dry rot in masonry and brickwork.

Step 7: Knowing how to treat dry rot

Different products can be used to treat dry rot in wood. Some of these products go into the wood, while others coat the wood’s surface. The surface of the wood can be painted with fungicidal gel, which comes in different concentrations depending on whether you want to stop dry rot or treat it.

What is wet rot?

Wet rot is a term used to describe various species of fungi that can cause significant damage to properties if left untreated.

Coniophora Puteana is the most common fungus associated with wet rot, but several others can cause the same problem.

The growth of wet rot fungus is activated when the moisture content in the surrounding environment reaches 50%, resulting from water leaks, poor ventilation, or any other form of water ingress.

The common areas where wet rot is usually found include basements, roofs, and timbers around windows. If not treated promptly, wet rot can spread and cause significant structural damage, but the good news is that it does not spread through masonry.

What Causes Wet Rot?

The presence of moisture in the surrounding environment causes wet rot. The excess water provides an ideal breeding ground for the fungus to grow and feed on the timber, causing it to deteriorate over time. Wet rot only affects wood or timber that has been wet for an extended period and has 30-60% moisture content levels. This can happen due to several factors, including:

  • Plumbing leaks
  • Guttering leaks
  • Roof leaks
  • Pipe leaks
  • Leaking washing machines

Identifying Wet Rot: Key Signs to Look For

Certain signs and characteristics in timber can easily distinguish wet rot. If you suspect you have wet rot in your home, it’s important to take note of the following indicators:

Shrunken and Cracked Timber: Fungus-infested wood is prone to shrinking, leading to cracks and splits.

Soft and Spongy Touch: Wet rot often leaves the wood feeling soft and spongy to the touch.

Discoloration: The timber may have a noticeable discoloration, often appearing darker than its original shade.

Mycelium Strands: Sometimes, you may see mycelium strands growing on the wood.

Limited Spread: Wet rot stays confined to damp areas and does not spread to dry areas.

Damaged Paint Finish: The paint finish may appear damaged and flaky, revealing the cracked timber.

Musty Smell: Wet rot is often accompanied by a damp and musty odor, similar to rotting soil.

Wet rot can also appear in different forms, including white rot and brown rot. White rot tends to have a whitish appearance, while brown rot resembles the original timber color with a brownish hue.

It’s important to remember that wet rot may not always be visible, especially if the timber is painted or hidden behind a wall. If you detect a damp and musty smell or a screwdriver easily penetrates the wood, you are likely dealing with wet rot.

Where does the wet rot start to grow?

Wet rot is a fungus that grows well in humid environments. This means that parts of your house or property prone to dampness, such as your roof or flooring, can easily become infected. If wet rot is not taken care of, it can significantly harm your home’s building.

It’s crucial to remember that various varieties of wet rot fungi can only develop in areas with water.

On the bright side, the fungus won’t spread through the bricks. Once the moisture source is removed, wet rot growth will stop.

Many things can cause dampness, like rising dampness, leaky roofs, gutters, or faulty masonry pointing. These factors could create an environment perfect for wet rot to grow. However, it’s important to note that the fungus will only exist in the immediate area of the source of dampness.

How to Effectively Treat Wet Rot: A Step-by-Step Guide

Wet rot is a frustrating and damaging problem in many homes. However, with a little know-how, it can be prevented and treated effectively.

This guide will walk you through the steps you need to take to treat wet rot and protect your property.

Step 1: Find the Source of Moisture

The first step in treating wet rot is finding the moisture source. If you can’t find the source, you may need to get a professional wet rot survey.

Step 2: Dry Out the Affected Area

Dry out the affected area to see which timber has been impacted by the wet rot and needs to be removed.

Step 3: Remove Weakened Timber

Once the area is dry, remove any structural timber that the wet rot has severely damaged.

Step 4: Evaluate the Scope of the Work

Evaluate how much work must be done to treat the wet rot effectively. You may need to replace entire sections of timber or splice new timber onto old.

Step 5: Treat New and Surrounding Wood

Treat all new and surrounding wood with a high-quality preservative to prevent fungal regrowth. Allow the area to dry before sealing it to ensure the wet rot is fully treated.

Step 6: Remain Vigilant

Stay vigilant for any indication of wet rot reappearing and take care of it quickly. Doing regular check-ups will assist you in discovering fresh outbreaks of wet rot in its early stages, stopping any further harm from occurring.

Step 7: Get Professional Treatment

If the wet rot affects an area that could compromise your home’s structural integrity, it’s best to get professional treatment. Professional treatment can ensure that the problem is dealt with effectively and protect the structural integrity of your home.

How much it cost to treat wet rot and dry rot

The price of fixing wood rot can change based on different things, such as how bad the damage is, where it is located, who you hire to do the job, and where the property is located.

A professional survey and repairs are needed to eliminate dry rot, and the cost can range from $100 to $50,000, depending on the extent of the damage.

To repair dry rot, a professional might charge $100 to $300 for a single, easy-to-access area. If the dry rot affects larger areas, such as siding or floor joists, the cost could be between $1,000 to $12,000.

If you want to do the repairs yourself, a DIY project can cost you around $50 to $150, but this approach is not always effective.

For wet rot, the cost is similar to dry rot, but it may be easier to detect early, reducing the repair cost. If you need to replace timber that the rot has compromised, the cost can range from $150 to $25,000+.

Repairing a small roof can cost $150 to $400 or $50 to $100 per hour, and fixing wood rot around a window can cost around $180 to $400.

The final cost will depend on several factors, and it’s best to get quotes from licensed contractors for an accurate estimate.


Dry rot is treated by cutting out infected wood, treating it with fungicide, and improving ventilation.

Wet rot is treated by removing and replacing affected wood, finding the source of moisture, using a fungicide and wood hardener, and increasing airflow.

Pre-treated wood is more effective in slowing down the rotting process. It’s important to act quickly to prevent further damage by assessing the source of moisture, clearing the affected area, strengthening weakened structural timber, treating adjacent timbers with a fungicide, dealing with the extent of the rot, and remaining vigilant.