Woodworm treatments

[Pirou]

Hi all,

We are about to shut up our house for the winter. Is there a product (a so called bomb/bombe) which we can set off as we leave which will fumigate the house and kill bugs particularly woodworm? The woodworm has been treated this summer with a paint on product and we followed the instructions and painted it on as thoroughly as we could but 6 weeks later there is some activity again and I'm finding wood dust under the beams and from the wooden planked ceiling itself. It's oak we think.

I wondered if there was a bomb product anyone has used and can recommend. We've talked to the bricolage stores but what we've been shown doesn't seem to indicate it will deal with woodworm specifically.

Happy to hear any advice or opinions. Thanks.

[andyh4]

You can get smoke bombs and these are usually found on the tool lorries that do their rounds at the markets. These are the trucks that tend to sell the cheap Chinese tools that break within the first week of use. IMHO the bombs are in the same category.

The problem with these cheap style bombs is that they deposit a fine dust of poison on all surfaces. This will include (for example) the inside of your cutlery draw - so do wash everything when you get back before you use it. It will also deposit said poison on all wood surfaces. Any beetles wandering around on the wood surface could pick up enough of the settled dust to kill it but may well not. Beetles emerging from the wood may well eat enough of the poison to kill them. But that is rather shutting the stable door after the beetle has eaten it.

IMO the better solution is the liquid style materials that you have already used. However I would spray rather than paint. You really need to get a heavy loading of liquid absorbed into the wood, and brushing on just does not do this.

Spray the poison on using a garden sprayer. Make sure that you are fully protected with disposable overalls, goggles, gloves, wellington boots and most important of all a proper face mask suitable to protect from aerosols - this is a proper jobbie with a cartridge and not one of those clip over your nose jobs which only protect from dust. You are now ready to start chemical warfare - and indeed that is what this is all about. Give a heavy spray over all wood surfaces paying particular attention around joints where you cannot get full access to the end grain. Give at least 3 coats with each coat being applied before the previous one has dried. Do not be tempted to just spray around the area where there are holes. These are flight holes and will be empty - the beetles have gone.

Hard woods like oak are more difficult to treat because the liquid does not penetrate very deeply - which is why several coats are recommended. If the wood is covered with paint, varnish or even wax this will minimise the penetration of the liquid and such surfaces are best removed before you start.

There are other treatment methods relying on putting Boron compounds into the wood, but I have not tried these so cannot comment on ease of use or the effectiveness.

[Pirou]

Andy, I'm very late in saying thank you for all your advice. I took note of all your points particularly about the bombe poison residue and decided to buy a sprayer and disposable jumpsuit (bought in England) and followed all your suggestions and precautions. We did the spraying the day before we left in autumn and moved into a b and b for the night so we weren't shut in with the fumes. Then we shut up the house the following day.

The treatments seem to have worked as we have very little sign of woodworm activity but perhaps that is because they are less active in winter. Anyway, I wanted to thank you for your post because it was very useful and great guidance.

[andyh4]

I wish I could tell you that you have clearly solved the problem, but the reality is (as you surmised) that the beetles only emerge in warm weather - usually April/May onwards.

You will only know then if you have won, or whether another dosing is going to be needed.