Woodworm treatment recommendations

[sammy.se]

Hi,
The work to remediate the damp problems in my dining room is going well... The job has grown (don't they all) and as well as removing the hearth and cubic metre of clay, I've replaced all the rotten and woodworm infested joists wallplates and most of the floorboards.

unfortunately, I've discovered some bad woodworm in floorboards and joists in the adjoining passage. I'm replacing what I can but I won't be able to reach everywhere (under the stairs).

Can anybody recommend a good, strong treatment, either a liquid I can spray on, or a smoke/ aerosol type bug bomb?

The damp issues is probably what attracted the woodworm to begin with

Thanks!

 

[Doug71]

I have used this stuff in the past but only brushed it on, guess you could put it in a garden type sprayer.

Really easy to apply, dries quickly and doesn't smell.


https://www.screwfix.com/p/sika-sik...tr/56214#product_additional_details_container

 

[sammy.se]

Thanks Doug, yes I did see that in Screwfix and in fact bought that one for my immediate needs.

I was particularly looking for experience/recommendations around any concentrated versions, since I have a large area to cover in two coats, e.g. this product:

https://www.permagard.co.uk/insecticide-woodworm-treatment
And also, any bug bomb / smoke type treatments, if anyone knows of good brands they recommend.

 

[Sgian Dubh]

Standard woodworm treatments, including both of those listed already, have the active ingredient permethrin. Permethrin treatment in this form is topical (sprayed, brushed on) and should kill adults as they emerge from wood after their larval stage because it is a contact pesticide that passes through the insect’s outer layer or cuticle into the body and primarily affects the nervous system. The same poison will kill larvae emerging from the egg assuming the egg is not too deep, and it can kill larvae near the wood surface, and it does discourage adult females from laying eggs. A typical flooding application of the poison to the whole wood surface results in penetration into the wood of between 2- 6 mm, and frequently two or three floodings are required to achieve this sort of penetration into the wood fibres. Repeat doses are required over a long period to be effective.

I can't recommend bombs and the like, but these generally include tenting up the house to seal it, and then fumigating the entire property with insecticide released as a vapour able to penetrate nooks and crannies. It's quite an involved operation requiring a fair amount of time, as I'm sure you can imagine. Slainte.

 

[sunnybob]

My usual recommendation for the treatment of woodworm might not be apt in this particular instance. But just in case,,,,, is your house fire insurance adequate?

 

[sammy.se]

Standard woodworm treatments, including both of those listed already, have the active ingredient permethrin. Permethrin treatment in this form is topical (sprayed, brushed on) and should kill adults as they emerge from wood after their larval stage because it is a contact pesticide that passes through the insect’s outer layer or cuticle into the body and primarily affects the nervous system. The same poison will kill larvae emerging from the egg assuming the egg is not too deep, and it can kill larvae near the wood surface, and it does discourage adult females from laying eggs. A typical flooding application of the poison to the whole wood surface results in penetration into the wood of between 2- 6 mm, and frequently two or three floodings are required to achieve this sort of penetration into the wood fibres. Repeat doses are required over a long period to be effective.

I can't recommend bombs and the like, but these generally include tenting up the house to seal it, and then fumigating the entire property with insecticide released as a vapour able to penetrate nooks and crannies. It's quite an involved operation requiring a fair amount of time, as I'm sure you can imagine. Slainte.

Thank you. I think this is my best current option. I don't mind repeating the treatment every few months or so.

So far, it has only affected very localised areas of the house, but I will spray everything I can reach as a preventative measure.

I assume it's localised to a couple of joists and floorboards due to the damp that is there? The rest of the house is very dry, so I think I need to worry less... Or...?

 

[Sgian Dubh]

Thank you. I think this is my best current option. I don't mind repeating the treatment every few months or so.

So far, it has only affected very localised areas of the house, but I will spray everything I can reach as a preventative measure.

I assume it's localised to a couple of joists and floorboards due to the damp that is there? The rest of the house is very dry, so I think I need to worry less... Or...?

It largely depends upon the dryness of the wood. About 12 - 13% wood MC is pretty much the lowest MC in which common furniture beetle grubs can survive - 12% MC and lower is reckoned to be too dry for the grubs. So, for example, if the end of a joist or floorboard is pretty wet, say ~20 - 25% MC and above, that's fine for the grubs, but they're unlikely to stray much into stuff further along the joist if its' sub, say 15 or 16% MC.

In general, common furniture beetle is unlikely to be a problem inside habitable buildings with good climate control because the wood's too dry, but they can be a problem in parts of a habitable building where wood MC tends to be higher, e.g., roof spaces, soffits, under eaves, porches, etc, and in buildings such as unheated and drafty barns, sheds, outhouses and the like. That certainly applies in cool temperate climates (UK for e.g.), but I'm not sure what the climate is like where you are, Cyprus, I think. Slainte.

 

[sammy.se]

Thank you @Sgian Dubh , very insightful.

Yes, the infestation seems very localised to the damp area, I shall keep an eye on the MC of the wood.

 

[MIGNAL]

When I was house bashing, many years ago, all the woodworm infestations were due to damp. Being an electricians mate you get to see all parts of the house. I can only ever remember seeing woodworm damage in cellars (quite often, including my own!), under baths that had obviously leaked and roof spaces that had been open to the elements.
If you can keep the spaces well ventilated I wouldn't bother with the chemicals. I once had an infestation in my workshop, brought in from storing some rather expensive violin wood for a friend. During the early spring I could see them emerging from the wood, often landing on the white painted walls of the workshop. He later admitted that it had been previously stored in a damp room but had no choice due to house moves. My wood was stored right next to the wood that was infested. I did nothing, I knew that they wouldn't go for my wood. They flew off to better pastures. My attic workshop was far too dry for them. In 35 years it's the only time I've ever seen anobium in my workshop. The infestation was 20 years ago. I think they've long gone.