Woodworm Treatment Products: What to Buy and What to Avoid
Unsure which woodworm product to buy? Learn how sprays, pastes and injection fluids differ, what the label should say and when a product will not be enough.
Shops sell many woodworm products, and the labels all sound alike. This guide explains the main types, what to check before you buy and when a product will not be enough. We have not tested products, so we name no brands.
The main types
Water-based sprays
These contain an insecticide, often permethrin, in a water-based mix. You brush or spray them onto bare wood. They suit furniture, shelving and open timber, because they soak the surface layers. Read about the method on our spray treatment page.
Pastes and gels
These hold boron or another active ingredient against the wood. They spread through damp timber over time. They suit thick wood and joist ends, as our page on boron paste explains.
Injection fluids
Some kits let you inject fluid into holes. This helps with furniture and small joinery, because the fluid reaches inside the hole. Use the nozzle that comes with the kit.
What the label should say
Check four things before you buy:
- It names the target insect, such as wood-boring beetle
- It states the active ingredient
- It says how much to use per square metre
- It lists safety steps and drying times
If a label hides the ingredient or makes big promises, choose another product. Always read the safety data sheet too.
Safety
Wear gloves and a mask, and work in fresh air. Keep children and pets away until the wood is dry. Permethrin is toxic to cats and fish, so cover tanks and keep cats out. Follow the disposal advice on the label.
What products cannot do
A product treats the wood. It does not fix damp, and it does not restore lost strength. For that reason, fix leaks first and replace weak timber.
A shop product also may not reach deep enough in thick joists or beams. In those cases, a surveyor may advise paste or another method. Our guide to DIY versus professional treatment explains the trade-offs.
Natural and home remedies
Vinegar, essential oils and household sprays have little evidence behind them. Boron is the main exception, because borates are a recognised wood treatment. Read our guide to natural woodworm treatment for more.
Common mistakes
Avoid these mistakes:
- Treating old holes that are not active
- Skipping the underside and the ends of the wood
- Using a lubricant or oil instead of an insecticide
- Ignoring damp
The post on treating woodworm with WD-40 explains why a lubricant is not a treatment.
Before you buy
Check that the beetle is active. Our guide to signs of woodworm shows how. If you are unsure, a survey saves money.
Where you live matters, because older streets hold more old timber. See our local guides for woodworm treatment in Birmingham and woodworm treatment in Glasgow.
To go deeper, read about the spray treatment and the boron paste treatment, because the right method depends on the beetle.