Woodworm treatment

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Just renovating an 18th century cottage. There are lots of woodworm holes in the beams but not sure if it is active - unless dust on the window sill is frass. Is it too early in the year to spot any beetles? The surveyor who went into the loft thinks there may be some activity there 'due to the neat holes'. but nothing else observed. I note his report says things like evidence of slight to moderate infestation - the word 'active' is not used. Is this a red flag?
That said I thought a treatment with guarantee would at least help with future saleability. Plus now's the time to do something like this - before I actually move in and discover that it is actually active!
The bedroom above the kitchen has had a new floor at some point which has been hardboarded over. The exposed joists in the kitchen below look perfect. But to get a proper look at the floorboards or carry out any treatment would need removal of the hardboard.
The loft is insulated and the insulation is in good condition. I was told they could either treat and leave the insulation in situ or I would have to get someone to remove the insulation. Actually I was surprised he even suggested leaving the insulation in situ. Apart from only doing half a job, wouldn't the insulation become contaminated? (water based permethrin).
I still need to read through the guarantee carefully but as I understand it, it only applies to the treated wood. What would you do about the insulation and the bedroom floor? Is doing 'most' of the house better than nothing?
 
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I have to say, I have witnessed treatments by reputable companies who have treated woodworm, and I wasn't impressed......if anything was in the way of the timbers, nothing was moved to allow access and that includes the insulation.
The surveyor is guarding his private parts, really......a neat beetle exit hole is no guarantee of whether the infestation is historic or current.
Personally I would drench all of the suspect timbers with treatment as far as possible, and as you will be doing a complete renovation by the sound of it, continue as you go. If you suspect any nasties in the loft, then shift that insulation.
Was the floor replaced due to woodworm, do you know? If it was, then presumably the joists below were also affected.
John :)
 
Thanks John
The previous owner is not fessing up if it was him. That said it looks as if he kept it as a poorly maintained personal holiday cottage for 25 years and any work was down to the previous owner. The lounge ceiling is all original exposed timbers and joists - so you can see the bedroom floorboards which seem OK. The ancient beams have had a good bit of (historic we hope) chomping but are structurally sound.
The window lintels also have holes - and a bit of dust has been appearing on the ledge below.
In the kitchen below the boarded bedroom there are exposed joists as well as two original beams. The joists are modern saw cut and look untouched.
To be honest if I get professionals in - the guy that came was from one of two big names in the business - it's partly for the sake of the guarantee for future resale. My understanding is that most mortgage providers would demand it.
Btw I have a dog whose health condition means avoiding any toxins and I do worry about soaking my timbers in insecticide even though I am assured it is safe.
 
You would be hard pushed to NOT find insect holes in the timbers of any old building (or even new ones).

Often historic, often damage caused when it was still a 'wet' log, old hardwood beams may have chewed up sapwood as this contains starch (which depletes after 15 or so years).

Getting woodworm attack in dry timber is possible, but so is winning the lottery.

The guarantee's are usually useless as well, in that they often have a clause the exempts them from insect or rot caused by moisture ingress (which is the only time the timbers will be at any reasonable risk).

If you want to do it for saleability OK.
 
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what timber is it?do you know what species of beetle you may have?
what treatment have you bought?

put some white paper down on the joists give it a bit of time and see if any fresh frass has landed on the paper.
better to remove all the insulation so that you can get to 3 sides of the timbers,plus if its a spirit fluid your using then its a fire risk.
 
Thanks I'm assuming oak timbers but I don't know.
There has been a bit of dust underneath the window lintels. I don't know if this is frass or old dust coming out due to the new activity in the house.
I suppose I ought to give the wood a good clean then stick loo paper over it to see if anything is emerging?
There were also some tiny pellet shapes which he said was due to some sort of weevil and which would be ok once a nearby wall cupboard has dried out.
The rest of the timbers look as if the damage is historic - I had paper underneath them and nothing.
All I know about the the treatment is that it is a water based permethrin solution. I had to ask. Though the company is one of the ''big names' I'm not happy that they don't specify this - or the insect - in the quote.
 
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I know I mentioned this trick in an earlier post, but is it possible to block the holes up with some filler.....just a quick wipe over? At least you'll see over time if there are any new ones!
Expect dust to appear when there is any hammering activity in the region so this could well be a false alarm.
The water based treatment shouldn't give off any smell after a while.
John :)
 
The company is saying it doesn't treat painted or varnished wood unless it is stripped. I have yet to find out if this also applies to stained wood - as I suspect the exposed ceiling timbers in the lounge are - :(
 
If this situation was mine, I think I'd be treating any infected beams (and the immediate surrounding areas) with a brush on worm killer, keep an eye on the situation for future exit holes and if anyone questioned things, I'd say the worm was historic and has been treated.
Who's to say otherwise......and as for any company admitting to any liability for woodworm in the future, there's next to no chance of success.
I think Aron is bang on here!
John :)
 
one of the get clauses of guarantees is even though its been treated it wont stop the beetle from emerging,google life cycles of woodworm and differing types.the flight holes are when the beetle has matured and will eat itself out from the timber =flight holes.they will eat the treated timber and will mate and start the process all over again.it may take 2-3 life cycles to be free from worm.
we used to use a spirit based fluid on hardwoods as this used to help to get the preservative into the timber,but i assume they now have the equivalent in water borne fluids that are used on oak and the like.
i agree with what they have said about painted/varnished timber as the fluid has no where to go about from evaporating on the surface.
as a hunch at the age of your house id say the beetle you have is death watch,search on line about it and possible treatments.certain companys can supply a mayonnaise jelly/paste that can be smeared onto the timber.
 
Cheers folks. I do hope it is not death watch! Eek! Just to let you know I have bitten the bullet and arranged for a treatment after negotiating the quote down. The theory these firms tout is that the emerging beetle will eat it's way out, encounter the poison and die - so the life cycle is broken and infestation is at least controlled. Personally I think much of this is an expensive 'p' take and feel a traitor to the cause having it done but I'm not really capable of crawling round the roof space to do it myself and having this silly 'guarantee' will help with any resale - which could be within the next 2 or 3 years.
My friendly builder is removing the loft insulation today (for a price). It then remains to be seen whether I can get it hauled back again or whether I will have to get new.
 
before your heart sinks about death watch beetle,do read up about it.
 

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