A woman at Fairy Meadow rang me about a sideboard.
She'd taken it out of her mother's place when the house was being cleared, spent a Saturday getting forty years of polish off the back of it, and found a scatter of small round holes across the bottom panel. Maybe thirty of them, each about the width of a pin. She looked it up that night, read enough to frighten herself properly, and by Sunday morning the sideboard was in the garage under a tarp and she was asking me whether the whole house needed doing.
Some version of this call comes in every couple of months, usually after a clearing sale or a Marketplace pickup. It nearly always ends the same way. The holes are real. Whatever made them left a long time ago.
Every hole you can see is an exit
Here's the part that reframes the whole thing, and almost nobody knows it.
A borer doesn't chew its way into your furniture. The female lays eggs into the timber, the grub hatches and spends months or years tunnelling around inside eating, and when it's finished it pupates and the adult beetle chews its way out. The Australian Museum's page on the Powder Post Borer sets the sequence out plainly: eggs into hardwood, grubs feeding on the starch in the wood, larvae pupating into adults that then bore their way out.
A hole is a departure notice.
Which means counting holes tells you close to nothing about whether anything is alive in there now. A piece with two hundred holes in it and nothing living inside is harmless furniture. A piece with four holes and a grub still working through the leg is the one worth acting on. People read it exactly backwards, and I don't blame them, because the holes are the only part you can actually see.
The other useful number from that page: powder post borer exit holes run about two millimetres across, and the beetle itself is only three or four millimetres long. If you're looking at holes you could get a pencil into, that's something other than a powder post borer and it's worth ringing somebody before you do anything else.
The dust is the tell, and the test is free
Frass is the fine powder that comes out of the holes. It's part sawdust, part beetle. With a lyctine borer it's genuinely flour-like, and it will sit in a little cone under the piece or drift down when you knock the timber.
Here's how I actually settle the question, and you can do it yourself without paying anyone.
Vacuum the piece properly, holes and all, then wipe it down. Stand it on a sheet of white paper or an old bedsheet somewhere you won't disturb it. Then leave it alone for two or three weeks and go and look. Fresh powder on the paper means something is still working in there. Nothing on the paper means you've most likely got a finished job.
Do it in the warmer months if you can. Winter in the Illawarra slows everything down and a cold garage in July can hand you a false all-clear.
While you're at it, look at the holes themselves under a decent light. A fresh exit hole has clean pale edges and looks like it was drilled yesterday. An old one is darkened, softened at the rim, and very often has polish or wax sitting in it from somebody's re-finish twenty years ago. That last one is the giveaway on inherited furniture. If the shellac has run into the hole, the hole was there before the shellac.
Why most of what I see is old damage
The grub is eating starch, and there's only so much of it.
Starch sits in the sapwood, the paler outer band of the log, and not in the heartwood. Once a generation of grubs has worked through the starch in a board, the board stops being food. That's the whole reason a lyctine infestation in a finished piece of furniture burns itself out rather than eating forever, and it's why so many old pieces are riddled and stable at the same time.
It's also why this is a much smaller deal for your house than the internet suggests. Because these borers only get into susceptible sapwood, the rules for building materials deal with the problem at the source. The museum notes that New South Wales legislation only allows a limited amount of susceptible timber to be used in building construction, which is why I almost never find borer damage in the structural frame of a house built in the last few decades. Old joinery, old flooring, old furniture, yes. Bearers and joists, rarely.
Termites are the pest that eats a house. Borers, most of the time, are the pest that eats a chair. They get lumped together because both are timber pests and both show up in the same inspection, and the anxiety gets transferred across.
The ones that are worth a second look
Not everything is old damage, so a few things make me take a piece more seriously.
Fresh powder on the paper after three weeks in warm weather. Holes with clean pale rims on a piece that hasn't been re-finished. A grub actually visible where a bit of veneer has lifted. Any of those and the thing is live.
The other one is old seasoned softwood, which is a different family of borer and a slower, longer story. That's the damage I see in hundred-year-old pine flooring, old church pews, the odd cedar wardrobe. It's uncommon in the Illawarra compared to what turns up in colder parts of the country, but it exists, and unlike the powder post borers it isn't guaranteed to run out of food and stop.
What treating a piece actually involves
Most of the time, honestly, nothing. If the paper stays clean, you have a piece of furniture with character and you should put it back in the dining room.
If it is live, the sensible options come down to killing what's inside a single portable object rather than treating a building. There's a chemical route, and there's a heat or freezing route that a furniture restorer or conservator will often be better set up for than I am, particularly on something with veneer, inlay or an original finish worth protecting. I'd rather send you to the right trade than sell you a spray.
If it does go down the chemical road, two things are worth knowing about how that's regulated. Anyone applying pesticide as part of their job in New South Wales works under the EPA, and the rules for occupational pesticide users are not suggestions: it's illegal to apply a product in this state unless it's registered by the APVMA with an approved label, and it's illegal to disregard the label instructions once you're using it. So the honest answer to "can you just put something on it" is that it depends entirely on whether there's a registered product whose label covers that use, applied the way the label says.
What nobody should be doing is fumigating a house because of a bookcase.
And the boring advice that prevents most of this: when you bring second-hand timber furniture home, give it a fortnight in the garage on a sheet of paper before it comes inside. Especially if you've got an older place with original pine floors. Two weeks of patience is cheaper than every other option on this page.
When it isn't the furniture, it's the house
Occasionally it is the building, and that's a different conversation.
Borers turn up in old flooring, in the underside of a staircase, in window joinery on a Federation place, in a subfloor where somebody used recycled timber. They're part of what a timber pest inspection covers, alongside termites and wood decay, which is why the inspection is a broader job than most people expect when they book it. What's actually checked is on the timber pest and termite inspection page.
If you're buying, this matters more than it sounds. A borer finding in a pre-purchase report that reads "old, inactive, no treatment recommended" is a completely legitimate result and not an inspector hedging. It's also the kind of line that panics buyers into walking away from a good house, or into paying for a treatment that has nothing to treat. The difference between the pest half and the building half of that inspection, and why the pest half is the half that wrongly gets skipped, is in the pest half of a building and pest inspection. What the inspection itself costs around here, and what moves the price, is in what a termite inspection costs in the Illawarra.
What happened with the sideboard
I had a look at it on a Thursday. Every hole was dark, the rims were soft, and three of them had polish sitting in the bottom. The panel was hardwood sapwood, exactly what a powder post borer wants, and it had been a good feed at some point in the 1970s.
I told her to run the paper test anyway, because I'd rather be shown wrong by a bedsheet than talk somebody out of worrying. Three weeks later she sent me a photo of a clean sheet and the sideboard back against the dining room wall.
If you've got a piece with holes in it and you'd like a straight answer rather than a treatment, send us a photo. Get the light across the surface at a low angle so the holes cast a shadow, and include a coin for scale. Nine times out of ten I can tell you it's finished, and it costs you nothing to ask.
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