Should you buy a house with woodworm?

The surveyor has written the word woodworm in your home report, and somewhere between that sentence and your solicitor asking what you want to do, the purchase has started to feel like a mistake.

Here is the short version. In most cases, yes, you should still buy the house. The large majority of woodworm found in Scottish property is historic: beetles that finished decades ago, in timber that is still perfectly sound, in a floor that has since dried out. Treating it would achieve nothing, and it is not a reason to lose a house you want.

But “most cases” is not “all cases”, and the difference between the two is worth about four figures on the price, occasionally five. What follows is how to work out which one you are looking at, inside the fortnight a Scottish purchase usually gives you.

The three questions that actually decide it

Forget whether there is woodworm. There is woodworm in an enormous number of Scottish houses. These are the questions that carry money:

1. Is it still live? Old holes need nothing. Live larvae need treatment, and treatment is cheap.
2. Has the timber lost strength? This is the expensive question. Beetles that left in 1970 can still have eaten enough out of a joist end to matter today.
3. What let it happen? Furniture beetle wants damp wood. Live woodworm is nearly always a damp problem wearing a different hat, and the damp is what costs money to fix.

Question three is the one buyers skip and the one that decides the bill. If a survey names woodworm and says nothing about moisture, it has answered the easy part.

What your home report will and will not tell you

The single survey inside a Scottish home report is a visual inspection by a chartered surveyor who did not lift your floorboards, did not move the seller’s furniture and was in the property for well under an hour. That is not a criticism of surveyors, it is the job they were instructed to do.

So the report tells you that something was visible from standing height in the rooms that were accessible. It does not tell you whether anything is alive, how far it runs under the floor, or whether the joist ends built into the gable are sound. A category 3 against timber decay usually means the surveyor saw enough to want somebody else to look properly, and that is exactly what it should mean.

Read the property questionnaire as well. The seller fills that one in themselves, and a previous treatment, an old leak or a replaced floor often shows up there in a way it never shows up in the survey.

Telling live from historic before you commit

You can do a surprising amount of this yourself in an hour at a second viewing, and it costs nothing but a torch.

Ask the selling agent for access with a torch and permission to lift one board. Most will agree, particularly if the property has been on the market a while. Then look inside the holes rather than at them: pale and sharp means recent, grey and softened means old. Check what month it is, because adult beetles emerge roughly May to August and a January inspection answers much less than a June one. The full method, including the tissue paper test, is set out in how to tell if woodworm is active.

Then press a penknife or a bradawl into the bottom edge of a joist near the wall. Sound timber resists. Timber that takes the blade to any real depth has lost section, and that is a different and more serious conversation than whether beetles are still chewing.

What it costs, and how that turns into an offer

Treatment for live common furniture beetle is one of the cheaper jobs in this trade. Spraying accessible timber in a room or a loft is a day’s work for two people. The figures are on woodworm treatment cost.

What costs real money is everything around it: lifting and relaying floors to get access, renewing joist ends that have lost their bearing, tracing and fixing whatever was keeping the timber wet, and making good afterwards. A quote of a few hundred pounds and a quote of several thousand can both be honest quotes for the same house, because they are answering different questions.

This is why a vague allowance is a poor way to negotiate. “There is woodworm, knock off two grand” invites the seller to say no, because neither of you knows whether two grand is generous or laughable. A written specialist report with a scope and a figure is much harder to argue with, and it is the single most effective thing you can put in front of a selling agent.

Where the mortgage comes into it

Lenders in Scotland take their view from the home report valuation, and the two things that tend to follow a timber decay note are a request for a specialist report and, sometimes, a retention.

A retention means the lender advances the loan minus the cost of the works, and releases the balance once they are satisfied the work has been done. It is not the lender refusing to lend. It does mean you need the difference in cash on the day of entry, which is the part that catches people out, so find out early rather than in the week before you move.

A specialist report is usually the faster route. Lenders generally want it from a firm that does this work, on headed paper, saying what is wrong, what is needed and what it costs. That is a normal thing to ask for, and it is what a woodworm survey produces.

When it genuinely is a reason to walk away

Rare, but real. Any of these should slow you right down.

• The joist ends have gone. Timber built into solid sandstone, at the wall, where you cannot see it, and a blade goes straight in. Structural work in an occupied tenement flat with a shared close is expensive and slow.
• It arrives with dry rot. Woodworm is an insect in damp wood. Serpula lacrymans is a fungus that travels through masonry away from its own moisture source, and it changes the scale of the job entirely. If both are named, read buying a house with dry rot before you do anything else.
• The holes are around 3mm in old oak. That may be deathwatch beetle, Xestobium rufovillosum, which usually means the timber was already decaying before the beetles ever arrived.
• Nobody will let anybody look. A seller who will not permit a specialist inspection before missives conclude is telling you something, and it is worth listening to.
• You could not absorb the worst case. If the gap between a five hundred pound job and a six thousand pound job would break you, buy something else. That is not pessimism, it is arithmetic.

Why this comes up so often in Scottish flats

The building stock explains most of it. A tenement floor is suspended timber over a void nobody has seen since the building went up, with joist ends bedded straight into solid stone that has no cavity and no damp proof course between the masonry and the wood. The airbricks that were meant to keep air moving through that void have spent a century being blocked by a flowerbed, a raised path, decking or a later back extension.

Add high rainfall, long wet autumns, and shared gutters and downpipes that under Scottish tenement law belong to every owner in the close and therefore in practice to nobody, and you get timber sitting slightly too damp, in the dark, for a very long time. That is a good home for furniture beetle and a bad one for your floor.

It also means the honest answer to “is this house unusual” is generally no. A ground floor flat in a Glasgow tenement with some old flight holes in the floor void is an ordinary Scottish property, not a wreck.

What to do this week

1. Read the report properly. Note the category, the exact rooms named, and whether moisture is mentioned anywhere near the timber comment.
2. Get back in with a torch. Second viewings are normal and nobody will think it odd. Look inside the holes, press a blade into a joist, photograph everything.
3. Book a specialist inspection. Ask for a written report with a scope and a price, not a verbal reassurance, because your solicitor and your lender both need paper.
4. Tell your solicitor before missives conclude. Once missives are concluded your negotiating position is gone. This is the deadline that matters and it arrives faster than people expect.
5. Negotiate on the written figure. Either a reduction in price, or the seller has the work carried out before entry with the guarantee assigned to you.

If you want somebody to look and tell you plainly whether it is live and whether the timber has lost strength, that is a woodworm survey, and “there is nothing here worth treating” is a perfectly good result to pay for. The team we work with covers the Central Belt and can usually work to a purchase deadline if you say at the outset that you have one.