Woodworm on Survey - what to do?

booksandbikes

Yet another woodworm and survey post. 🤦‍♀️ I've read through a lot of threads here about woodworm, and the general consensus seems to be that most woodworm is historic and if not, can be treated by the owner as DIY.

So, our survey has come back with everything fine except 'evidence of woodworm attack is present to some elements of the roof structure and also to some of the ceiling joists. A timber treatment specialist should undertake treatment to these timbers.'

Can someone please look at the attached photos and advise if it's something we can do ourselves, or if we should get a timber specialist, or is it reasonable to pass this on to the vendor and ask if they can do the treatment?

It looks like current woodworm (I assume that is frass)?  It looks pretty bad to me, but I'm not sure!

When I spoke to the surveyor for an update (but before he had produced the report) he said that it would need treatment, but has not caused any structural compromise. He also said it was only in two areas of the roof and the rest of the roof was fine.

FreeBear

Frass would suggest recent activity, but you only get that as the woodworm (beetles) make an exit. It is the larvae munching away unseen under the surface that is causing the damage, and it is difficult to say with any certainty if the infestation is currently active. Spraying toxic chemicals on to the timber might kill the little blighters that are near the surface. But the spray is unlikely to penetrate more than a few millimetres in to the wood.

One comment to make on those images - The loft insulation would benefit from topping up. Aim for a total depth of 300mm to meet current recommendations.

booksandbikes

Thanks - noted about the insulation. It is currently 200mm according to the EPC.

Spray is unlikely to penetrate whether it is a DIY job or a professional?  In that case, what is the solution - must be something we can do?

A lot of the woodworm treatment for DIY have very positive reviews, so I was assuming it would solve the problem.

Grizebeck

We did woodworm treatment ourselves.

FreeBear

booksandbikes said: Spray is unlikely to penetrate whether it is a DIY job or a professional?  In that case, what is the solution - must be something we can do?

A lot of the woodworm treatment for DIY have very positive reviews, so I was assuming it would solve the problem.

If you are happy to use toxic* chemicals and have the appropriate PPE, no reason you can't DIY treatment. If you need a certificate for the mortgage provider, then you'll have no choice in getting a company in to do the work.

Woodworm likes damp timber, so as long as you can keep the moisture content down to 10-15%, you shouldn't have a problem.

The main active ingredient in most woodworm treatments appears to be permethrin - LD50 (lethal dose to kill 50%) for humans is 1-2 grammes per kilo orally. Smaller doses (50-100mg/Kg) can induce neurological symptoms. Do not spray near animals, and NEVER dispose of it down the drain.

stuart45

Woodworm treatment depends on whether you want to kill the larvae, or just discourage adults from laying their eggs on the timber. There are different types of woodworm, the House Longhorn is probably the worst.
If you want to kill the larvae you need to drill into the timber to inject the poison into it deep enough to kill them. Spraying is more of a surface treatment to put off the adults.
As FreeBear said, keeping the timber around 10% means the adults are unlikely to want their kids breaking their teeth on hard timber.