In this brief guide, we discuss the question “ should I buy a house with woodworm?”

Buying a house with woodworm requires serious considerations to avoid buying a house which may require extensive repairs or may invalidate your home insurance or possibly even raise your home insurance premium if you have to claim on it.  

It may also be possible that after providing you with a mortgage offer or mortgage in principle the mortgage lender discovers that you have woodworm through the property survey and withdraws their mortgage offer.  

Some mortgage lenders may also insist that the woodworm is treated before they will allow you to complete on the mortgage. Most woodworm treatments will have a 30-year guarantee which gives the mortgage lender and you some peace of mind.

The only upside with buying a house with woodworm is that you may be able to negotiate a much better price with the seller due to the infestation.

Should I buy a house with woodworm?

You should not buy a house with woodworm unless you understand the extent of woodworm and you have certainty of what the woodworm treatment costs will be. 

Woodworm could cause your roof to begin to lose its structural integrity or cause your foundation to begin to sink lower and lower into the ground. 

This is why it is essential to get a property survey before you buy a house to ensure that the property you are buying isn’t infested with woodworm and if it is infested with woodworm to ensure you know how much woodworm is in the property and what the cost of treating the woodworm would be before you decide if you should buy a house with woodworm.

What is woodworm?

Woodworm is a Larvae which is left behind by wood-boring beetles of varying species. In the United Kingdom the most common wood-boring species which leaves behind this larvae are the House Longhorn Beetle (Hylotrupes bajulus)  Deathwatch Beetle (Xestobium rufuvillosum), Common Furniture Beetle (Anobium punctatum) and Powderpost Beetle (Lyctus brunneus). 

These woodboring species invade wood, eat the wood and then leave once they have reached a mature age. The only issue is that they leave behind their larvae which then repeat the process until woodworm treatment is done.

How to check if a house has woodworm?

You should check if a house has woodworm before you decide if you should buy a house with woodworm.

The most efficient way to do this is by carrying out a property survey. This will ensure that if you end up finding woodworm in the future and the property survey report indicated that there was no woodworm then the liability will be on the property survey company if you can prove that the woodworm would have been present when they carried out their survey checks.

You can check for woodworm yourself but it may be hard to diagnose if you do not have adequate experience of what to look for. Woodworm could be present in a home for many years without it being noticeable and woodworm doesn’t just affect old homes, it can also affect very new homes.

If you are deciding if you should buy a house with woodworm then you should check to see if it has woodworm yourself by doing the below:

Tip: remember the woodworm eggs or larvae may be so small that you will not notice them at first glance.

What are the signs of woodworm infestation?

You may find very small holes on your wood which maybe the size of a pen tip

You may find that these holes have some sort of dust or powder around their entrance. This is known as frass or bore dust. 

These are the droppings which are produced by the woodworm larvae as they dig and chew their way through your wood.

You may also see some of the adult wood-eating beetles emerge from some of the holes and go about their business. 

You may even see them at other parts of the house, away from the holes.

In some cases, you may not even find or see any holes but you will notice bore dust or frass on the floor or falling from the outer side of the wood. This signifies that there is a woodworm problem in the house.

You may also begin to notice that some edges or joints of wooden structures begin to appear crumbly.

You should note that not all of the above may indicate that there is an active woodworm situation in the home you want to buy. It could very well be the case that the woodworm has left and this is jus evidence from a previous woodworm infestation.

What to do before you by a house with woodworm?

If you are considering if you should buy a house with woodworm and you have discovered some of the signs above then there are a few things you could write down as your action plans once you have purchase the house or before.

Before you purchase the house you could decide to carryout a more thorough survey with a property survey company and ask them to focus especially on the woodworm so you can know the extent of the infestation before you buy the house. Once you have the property survey you can then decide on if to buy a house with woodworm or not.

If you decide to buy a house with woodworm then below are a few things you can do to ensure your house is in the best shape.

Test the humidity of your house

You should check to see what the humidity of your house is and then look to increase it if it needs to be increased. 

The wood boring beetles thrive when the moisture content in the house is above 20% although they may be able to exist with moisture as low as 12% for a limited period of time.

You should measure the humidity of the wood in your house using a timber moisture metre

A moisture level below 11% will be ideal so that any colonies of wood-eating beetles will slowly die out.  You should look to keep the humidity levels as low as possible and replace any infested wood structure which has been infested by woodworm to reduce ts ability to spread to other parts of the house.   You should also look to install electric fly traps which will kill any adult beetles which are emerging from the loft or places which are ventilated as the beetles will usually go to these cooler areas during the summer months.

Get a professional entomologists to evaluate

Getting a professional entomologist to evaluate the extent of the woodworm infestation before you buy a house with woodworm or prior to treating a house you have bought with woodworm is always a good idea as they will be able to define the type of treatment needed 

and at what cost.

It may be the case that the woodworm in your home does not need any treatment as it is not harmful.

Block the entry holes

Another thing you can do is block the holes which the grown beetles make when they go out to breed during the months of May and September. You can block the holes using masking tape, or painting it over with a coat emulsion. You should do this during the winter months.

Figure out the cost of repairs

Once you have established that a house you want to buy has woodworm you should then enquire from different vendors about the total cost of the woodworm treatment. If this cost is way beyond what you can afford to pay then you should consider if you should buy a house with woodworm or not.

It is very possible that the woodworm could spread to other parts of the house if not properly treated or the woodworm could return if the conditions are right for it.

The most important parts of the house which you should consider when looking at the woodworm damage are the joints, the roof and any suspended floor as these parts of the house cold cos significantly more to replace if the woodworm infestation has made them unsafe.

Above are the steps you can take after you have bought a home with Woodworm. If you dint feel sufficient or capable of taking these steps then you should consider if buying a house with woodworm is a good idea.

Woodworm treatment

There are different methods of woodworm treatment, they include:

Freezing: You can freeze some woodworm infested furniture to treat it.

Pesticides: You could also use pesticides and apply it to different affected surfaces to kill any adult beetles which come out.

Fumigation – Fumigation may also be relevant, especially for Deathwatch Beetle infestation in large structural hardwoods. 

You should consider the above treatment before buying a house with woodworm.

FAQs about buying a house with woodworm

Below are some of the frequently asked questions in relation to buying a house with woodworm.

Does House Insurance Cover woodworm?

No, most house insurance policies will not cover you for woodworm. You will need to request this as an additional cover from most house insurance providers.

How long does woodworm treatment last?

A typical woodworm treatment can take less than a day to complete and will usually come with a 30-year guarantee which ensures that most mortgage lenders will be willing to lend to you and it gives you some peace of mind.

How bad is woodworm?

Wood word isn’t always bad. In some cases, woodworm can definitely affect the structure of your house if the infestation destroys your timber frames but the woodworm can also be dormant and you can live with it for many years.

The House Longhorn Beetle is the most dangerous wood-boring beetle.

Should I be worried about woodworm?

Yes, you should be worried about woodworm and you should definitely get a survey done before you buy a house with woodworm. There is some woodworm which isn’t so infectious so you may not have to worry about it. This means it will not spread from timber to timber.

Are woodworm active in winter?

Woodworm is less active during the winter but this is because they prefer more humid weather. They will usually migrate to areas where there is ventilation and more humidity during the winter months. Woodworm will usually start during the summer months rather than winter.

Does woodworm go away?

Woodworm doesn’t just go away so you should avoid buying a house with woodworm without having any suitable plans on how to deal with it. Woodworm isn’t always a problem as it may not always spread but it can.

How much does it cost to treat a house for woodworm?

To treat a house for woodworm it can cost from £300 to £1500 depending on the severity of the woodworm. You may also have to replace timber frames in your house which have been heavily affected. This could end up costing you much more than the woodworm treatment.

Will fly spray kill woodworm?

Fly spray could kill the adult beetles which emerge from the holes which they have bore but it is incredibly unlikely that they will get to or destroy the larvae which are deep within the wood.

How long does woodworm live for?

Most female wood-boring beetles which cause woodworm will live for between ten and fourteen days whilst the male wood-boring beetles will live between three and four days.

What causes woodworm in house?

Woodworm is usually caused by damn environments which allow them to feel comfortable enough and start infesting the wood in your house. If you want to avoid woodworm then you should reduce the humidity level in your house to less than 12%.

How do you kill woodworm?

You should get a professional to help you kill the woodworm in your house by performing the relevant treatment. You can kill the woodworm by painting over the affected area with a woodworm treatment solution.

Do woodworm bite humans?

The beetles which cause woodworm do not bite humans normally but if they are starved of food they may bite humans. This could cause the affected area of the body to swell and for you to have allergic reactions.

Can woodworm go through carpet?

Yes, woodworm can go through the carpet with relative ease.

What does a woodworm look like?

A woodworm looks like very small holes in your wood which the entry points will usually have some dust-like material around. This is known as bore dust or frass caused when the beetles which cause woodworm bite through the wood.

What time of year is woodworm active?

The time of the year where woodworm is very active is during the months of May and September. If you are considering buying a home with Woodworm then this may be a good time as it will be easier to treat the woodworm and see the results of your treatment.

Does cold kill woodworm?

The cold could help but cold will not kill woodworm as when the temperature gets to a freezing point it could kill the larvae but not the eggs which are contained within it. This means more larvae will soon be produced and row to be wood-boring beetles.

Using cold(freezing)to treat woodworm is best done when the eggs are hatching during the spring months as this ensures that you get most of the active parts of the infestation but it isn’t the most reliable woodworm treatment for long term results.

Can woodworm live in dry wood?

Woodworm will usually not be able to live in dry wood as they prefer wood where there is some level of humidity.

How do you stop woodworm from spreading?

To stop woodworm from spreading in your house you should replace timber which has been seriously affected by woodworm in your house. You should also look to keep the humidity in your house well below 12% to prevent the woodworm from spreading.

Is woodworm easy to treat?

Woodworm can be relatively easy to treat by [porfessionals once they woodworm infestation has been properly diagnosed. Depending on the severity of the infestation, it can easily be treated by simply painting over the affected area.

In this brief guide discussed the question “ should I buy a house with woodworm “. If you have any questions or comments please let us know.

John Bate

John has 22 years of experience in financial services. This spans across financial research, financial services (As a qualified mortgage broker and underwriter), financial trading and sales at global investment banks. While working as a publishing research analyst, he covered European bank credit and advised institutional clients on investment strategies at both JP Morgan and Societe Generale. John has passed all three levels of the CFA (Chartered Financial Analyst) programme.