How to Sell a House with Dry Rot

You can sell a house with dry rot by repairing it first, or by selling it as it is with the problem disclosed and the repair cost reflected in the price. Dry rot can knock thousands of pounds off the house's value, and lenders may refuse a mortgage until it is cured.

Article updated: July 2026

What is Dry Rot?

Dry rot is a naturally occurring fungus that causes timber to rot. Dry rot fungus uses damp timber as its food base to help it develop and spread.

The most common household dry rot fungus is a brown rot fungus known as Serpula lacrymans or S. lacrymans for short.

While dry rot only actually destroys timber it can spread to other building materials such as brick, stone, plaster and even steel.

The Causes

Dry rot is caused when some wood is exposed to damp. Dry rot can be caused if your house has such problems as a leaking roof, broken or blocked gutters, leaking pipes or drains, a condensation problem, a faulty or no damp proof course or is subject to flooding.

Dry rot can occur in timber with a moisture content of more than 20% or so. Dry rot grows and spreads fast in timber with a moisture content of 30-40% or so.

The Tell-Tale Signs

Here are the main symptoms of dry rot:

1. An unpleasant smell. If your home smells damp, smells musty, or has a 'mushroomy' smell then you may have dry rot.
2. The presence of dry rot growth. Dry rot growth is white/grey and fluffy in nature.
   Dry rot fungus spreads through what is known as mycelium growth, which is made up of branching filaments known as hypha. Mycelium growth is one of the early stages of dry rot development. It can spread several millimetres every day.
3. The presence of fungal growth. The fungal growth of Serpula lacrymans is a rusty red or orange sponge-like structure made up of what are known as fruiting bodies or sporophores. This fungal growth occurs in the later stages of dry rot when the fruiting bodies release spores which settle on and infect more timber.
4. The appearance of the timber. Timber affected by dry rot is dark in colour and appears to be dried out, hence the name. It is cracked or broken up with what is known as cuboidal cracking.

What does Dry Rot Look Like?

Dry rot shows up in three ways: white or grey fluffy strands, a rusty red or orange sponge-like fungus, and dark, cracked timber. It grows in hidden, out-of-the-way places, so the signs are not always easy to spot.

Mycelium Growth

These white or grey strands are mycelium, one of the early stages of dry rot.

Fungus

The rusty red or orange fungus appears in the later stages. It releases spores, which settle on more timber and infect it.

Affected Timber

Timber with dry rot turns dark, looks dried out and cracks into small cube shapes.

What Does Dry Rot Smell Like?

Dry rot has an almost earthy smell, and many people describe it as smelling like mushrooms. The smell can vary from case to case. While the smell is unpleasant, breathing in the odour isn't particularly harmful although the damp conditions needed for rot to spread can be bad for elderly people, children and those with respiratory conditions. Also, there may be other fungi present, with more harmful spores.

As the dry rot spreads, the smell can grow stronger, which makes it harder to miss.

How Serious is It?

At its worst, dry rot can weaken the structure of your home so badly that major rebuilding work is needed. There has been at least one case where part of a building collapsed due to dry rot and resulted in fatalities, as reported in this Telegraph news article.

Although most cases of dry rot are not as bad as this they all have the potential to become serious because of the rate at which dry rot spreads.

Dry Rot Spores

Dry rot starts as microscopic spores which spread through the timber of your property. When they encounter the correct conditions they start to grow long white strands known as hyphae and as the hyphae germinate a mycelium mass is created. On their own and in large enough quantities the dry rot spores are fine orange dust, though you would be unlikely to ever see something like this.

The spores themselves are not harmful but the conditions they thrive in can be.

Dry Rot and Wet Rot - The Difference

The term 'dry rot' arises because wood affected by dry rot appears dry, even though it has been caused by damp. Timber affected by wet rot appears wet and is soft and spongy in appearance.

Both dry rot and wet rot are caused by a fungus, but different types. Wet rot fungus tends to be black, white or yellow in colour rather than the rusty red or orange colouring of dry rot.

The key difference between dry and wet rot is the moisture content needed to cause them. Wet rot occurs when the timber moisture content exceeds 50% compared to 20% for dry rot.

Wet rot doesn't spread in the same way as dry rot and will stop when the moisture content falls below 50%.

RICS explains how to tell the difference between dry rot and wet rot in its dry rot guide.

How to Prevent It

You can help prevent dry rot in three ways:

• Checking the outside of your home periodically for problems. For example, look for broken or slipped roof tiles, missing pointing to roofs, chimneys and walls, damaged lead flashings, blocked or leaking gutters and leaking pipes.
• Checking the inside of your home periodically for damp. For example, check ceilings and walls, including behind furniture and in cupboards, cellars and in the loft or attic.
• Ensuring that your home is dry and well ventilated. Aim to minimise or eliminate condensation on windows and other surfaces.

Treatment

If you suspect you have dry rot then the best course of action is to take advice from a surveyor or a specialist dry rot treatment company.

You can find details of specialist dry rot treatment companies from The Property Care Association.

A surveyor or specialist dry rot treatment company will undertake a dry rot survey. They will be able to properly diagnose your dry rot and create a treatment plan for it.

The successful treatment of dry rot is likely to involve:

1. Establishing the original cause of the dry rot and fixing it. For example, a roof leak.
2. Drying out the affected area to ensure the dry rot cannot return. For example, by providing proper damp proofing and good ventilation.
3. Treating and replacing timber and other building materials that have been affected by dry rot. This could involve cutting out and replacing timber that is affected and spraying the affected area with a fungicide.

How Much does it Cost to Fix Dry Rot?

AXA's dry rot guide puts the cost of removing it at £1,000 to £2,000 or more each time, before any repairs to the damage it has caused. The bill grows with how far it has spread, and a more extensive case could cost £20,000 to fix, as one case reported by the Sun shows.

Is Dry Rot Covered by Home Insurance?

In most cases, dry rot isn't covered by house insurance on a standard household insurance policy. Most home insurance policies have a clause which specifically excludes dry rot.

Insurance companies may cover dry rot that has been caused by something else that is insured, such as a flood or burst pipe, but no more than that.

Selling a House with Dry Rot

The big problem with dry rot is that it decreases the value of your property. Dry rot can knock thousands of pounds off the value of your house. Dry rot could mean that you will have to make expensive repairs before you can sell your house.

Dry rot and mortgages: The really big problem with dry rot is that it can make your house unmortgageable, and so hard to sell to anyone who needs a mortgage.

When you sell your house, a buyer's surveyor will check for dry rot and the signs of dry rot, as well as other serious problems. If dry rot is seen or suspected he or she will note this in the Homebuyer's Report or valuation survey. For the buyer, that survey is a key part of due diligence on a property.

Once your buyer finds out about the dry rot chances are they will reduce their offer or pull out and the sale will fall through.

If the survey reports dry rot, the buyer's bank or building society is likely to do one of three things. It may offer only a reduced mortgage. It may wait to lend until the dry rot has been cured. Or it may refuse a mortgage on the property altogether. If it refuses, your buyer cannot use that lender's mortgage.

So, if your house has dry rot you could look at fixing the problem before putting it onto the market. Obtain some quotes to find out how expensive it will be.

You may decide to repair the problem before marketing the property, or sell it in its current condition with the defect disclosed and the likely repair cost reflected in the price. An independent surveyor, estate agent and solicitor can help you understand the practical and legal implications before you choose a route.

If the experience has changed what you want from your next purchase, compare the wider investment-property market, current buy-to-let properties for sale and suitable below-market-value opportunities with survey and repair costs included in the appraisal.

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