Woodworm - Tritec 121

[lindy]

They have found some active woodworm in our loft, but luckily nothing anywhere else. Apparently we just need some timber treatment to the rear half of the loft with Tritec 121. I have to say I am totally convinced that the chap who came was genuine and he is a member of BWPDA. However, I know how knowledgable you all are and wondered if anyone has any experience of this product?

Thanks for any help

Lindy

 

[Nemesis]

BWPDA members also recommend chemical injection dampproofing and cement render. Genuinely.

It sounds like a noxious chemical to me. I have no idea if there are better alternatives.

How do you know you have a major live infestation?

 

[lindy]

Well the surveyor picked it up and so did he. We never told him what the surveyor said to see if it was genuine. He showed us it. Im not sure its major.

Would really love to use no chemicals but im not sure we have any choice.

 

[Nemesis]

The surveyor would possibly be guarding his back - any sign of an infestation however old will bring alarm... and of course anyone who makes a living spraying for woodworm will tell you it requires treatment.

It could be long flown...

 

[lindy]

How would I tell though? I chose a company that charges for the survey as I though at least that way they get some money and are not making it through treatment only.

That's the trouble, its knowing who to trust.

 

[shelli]

Hi Lindy

Don't want to be a worry wort at all - BUT - we had Peter Cox out as soon as we completed on purchase to spray every timber from 1st floor up - however they didn't lift up the floorboards as they said they would so there is no way that they got them all - still we had a severe infestation that had been ongoing for 200 years (we're talking joists that you could push your finger through - the Tokyo of the woodworm world!)

The point I'm making is - be there when they come and make sure that they don't miss a single bit - if loft is boarded anywhere lift boards - if you store any wood (furniture etc) up there check it thoroughly

We're a bit manic about woodworm as it's cost us lots of time and joinery to eradicate them

LOL

 

[Nemesis]

Well - there are surveyors and surveyors.

Personally if I was getting any treatment done (which might not be necessary if a building is kept dry woodworm can't thrive) I would choose firms with a track record in historic buildings - Hutton and Rostron, Ridout Associates, those sort of people.

Spraying anywhere and everywhere might make cash for the firms concerned but is probably not required.

Most woodworm attacks are long gone - leaving only the flight holes behind.

Before carrying out any major works on a period building I highly recommend a SPAB Homeowners Weekend course!

http://www.spab.org.uk

 

[MdB]

We're a bit manic about woodworm as it's cost us lots of time and joinery to eradicate them

From what others have said, a bit of heat and removal of moisture would have done the same thing (though you still have to repair the damage).

I've some signs of woodworm here and I'm doing absolutely nothing about it apart from monitoring. So far, I've not seen any evidence of new holes and keeping the property dry and warm should stop them coming back.

 

[shelli]

Yes - Sorry MdB absolutely right - its the damage caused that's the real problem - previous owner just treated one side of beams and woodstained over - so the l'al b**gers just turned round and munched the other side of beam instead - and, yes then they flew away - to the next beam or joist along!!
- Dont know how previous owners could sleep with all that munching going on - I imagine it sounded like a troop of soldiers marching up gravel path most nights!

 

[Nemesis]

I'm not sure that if there is a heavy infestation that doing nothing is an option, but certainly I'd see if the worm is active before spraying.

Much which is sprayed has long flown I suspect!

 

[PC]

Oh dear here we go again.

Controlling woodworm by ventilation and heating doesn't eradicate the little blighters. This will have no control in a roof void or sub floor area!

The issue is however, is the infestation active, if so it would normally be associated with fresh bore dust (woodworm poo) and very clean looking exit flight holes. Old holes in timbers should not justify chemical treatment.

You don't say how old your house is, but in my experience any thing over say 100years generally wouldnt have activity, although woodworm is quite common in roof timbers where high humidities can affect moisture content of sap wood etc even where good ventialtion exists.

If its not active you shouln't be treating it anyway COSHH regs!!! and is the infestation severe enough to justify treatment ....probably not!

My commnets relate to furniture beetle only (woodworm) and not Death Watch which is a different beasty all together.

You may be interested in a study that I carried out in relation to comments that central heating / ventilation controls woodworm this can be viewed on http://www.premier-heritage.co.uk/news_item001.aspx?NewsID=10

PC

 

[Nemesis]

I'll add this link again to this thread:

http://periodpropertyshop.co.uk/phpBB2/viewtopic.php?t=5925&postdays=0&postorder=asc&start=0

and this article by Brian Ridout:

http://www.buildingconservation.com/articles/pdf_insectdamage/insectdamage.pdf

 

[Flyfisher]

So, if I've got areas of active infestation, as evidenced by frass, what is the best course of action? Localised spraying? If so, what's the best thing to use?

 

[lindy]

My house was built around 1910 ish so is almost 100 years old.

When we went through the house he showed us evidence of historic woodworm in loads of places. He said nothing indicated anywhere there was any active woodworm now other than in a part of the loft space. Here he showed us fresh bore dust and said it was active. In his report, he says that there is a 'smal'l amount of active woodowrm. What does this mean in terms of it being treated - how is it ok to leave it if it is only a small amount?

He has said that the ventilation in the loft needs improving and this should stop any future woodworm.

The things is, ideally I would like to use no chemicals, but I dont want to ignore things that have to be treated.

Edited to add: I have read that some woodworm does not need treating. Should his report state the type of woodworm that is active. The remedy is for common furniture beetle so am guessing that is what it is.

 

[Matt Green]

Insect damage in the sapwood of structural timbers.


When wood-boring insect flight holes are discovered in a structural timber there is a fear the remainder of the timber will succumb to attack. This is not the case. Without chemical modification of the timber by fungal decay, only the sapwood in susceptible to insect attack at moisture contents over approximately 18%. The heartwood will remain impervious to attack due to the various chemicals it contains that confer its durability. With this knowledge it is possible to explain the patterns of insect damage frequently found in structural timbers in buildings.

Most old roofs will have old beetle holes, but these will be restricted to sapwood edges. The pattern of damage will reflect the way in which the log was converted to produce the roof components.

If the roof contain a large amount of sapwood and there were signs of active beetle infestation then this might be justifiable, but this is very uncommon in domestic roofs that date from prior to the First World War. A few rafters with sapwood damaged by furniture beetle usually means that the roof is not generally susceptible to beetle attack, not that it is vulnerable and requires treatment.

Quoted standard paragraph.

If you have active furniture beetle is your attic, some environmental factor must have changed to allow it to attack the sapwood, usually a roof leak or similar. If there is an obvious source of water, fix it. The timber will dry and the insects will leave. Regardless, the damage will be confined to the (outer) sapwood portions of the timbers.

A lack of ventilation did not cause the attack. Increasing it will not cure it.

The man you employed is a commissioned salesman, whether you paid him or not. He is selling blanket treatments, which would work, but would be an over-application of insecticide given the sapwood content of your roof represents a very small proportion of the total surface area that would be sprayed.

Apply any commercial insecticide with a brush to the affected area and there should be no further problems as long as there is no (further) water ingress. Anything containing permethrin will be suitably effective.

Matt Green

 

[Matt Green]

The point I'm making is - be there when they come and make sure that they don't miss a single bit - if loft is boarded anywhere lift boards - if you store any wood (furniture etc) up there check it thoroughly

We're a bit manic about woodworm as it's cost us lots of time and joinery to eradicate them

LOL

Oh the hilarity.

We needlessly sprayed our entire house with an organophosate when only a really small proportion of the timber was susceptible to infestation!

We did it on the word of a commissioned salesman who told us it was what we needed!

The house is still leaking, meaning that the gaurentee is void and the threat of damage remains the same- except we spent the money we could have used to fix it on insecticides!

And we can tell everyone else to do the same and perpetuate the cycle!

:evil: :evil: :evil: :evil: :evil:

Yeah, ******* ****** and futhermore: ****

I'm rolling in the aisles with laughter here.


Matt

 

[Nemesis]

I'm thinking of the damage which could be caused to historic floorboards by these people trying to lift them to spray.

I doubt they will take care and that they will be easily replaced afterwards!

 

[Lime]

The problem with some woodworm is they haven't read the literature.
I have seen wood so badly eaten throughout that the timber is very weak.
It does depend on the wood we are talking about though.
Some wood is much more prone to infestation than other wood even of the same type. I presume some tastes better than others to the woodworm beetle when laying eggs.
Live woodworm needs to be treated. High infestation starts with the first egg laid and when you see a flight hole the process of eating wood by that worm is over.
However old woodworm holes are often treated time after time completely unnecessarily. I make a habit of writing with pencil on treated wood (out of normal sight) with the chemical name etc and date.
What is not clear to me is whether or not modern treatments are effective in the long-term from reinfestation.
The older long-term chemicals are frowned upon now but they did stay active.

 

[Matt Green]

The problem with some woodworm is they haven't read the literature.

Furniture beetle only eat sapwood. Woodworm is a blanket term and isn't species specific. We're talking about furniture beetle here.

It does depend on the wood we are talking about though.
Some wood is much more prone to infestation than other wood even of the same type.

Furniture beetle will attack both hardwoods and softwoods. They like Elm sapwood. Timbers with a high proportion of sapwood are more susceptible to attack than those with a low proportion.

I presume some tastes better than others to the woodworm beetle when laying eggs.

More nitrogen in the sapwood.

Live woodworm needs to be treated.

No. It depends entirely on the quality of timber. Consider a purlin with a 10mm by 60mm sliver of sapwood with active furniture beetle in. It poses no threat to the rest of the member. The insects consume the sapwood and leave. As long as the heartwood remains dry, there is no further risk. No magic, no mystery, no grey area. Just fact.

Chemicals might give you a warm fuzzy feeling inside when you sleep at night under your cosy guarentee. I prefer to understand what I am trying to kill.



Matt

 

[Flyfisher]

The insects consume the sapwood and leave. As long as the heartwood remains dry, there is no further risk. No magic, no mystery, no grey area. Just fact.

Isn't the grey area whether or not the remaining heartwood is sufficiently strong enough for the structural purpose the wood is being used for?

If the (largely impervious) heartwood remains strong enough to keep my roof safe then I'm happy to let the beetles consume sapwood to their hearts content, if not, then I'm afraid it has to be chemical warfare. Such a judgement seems more like a matter for a structural architect than a woodworm salesman, to me.

In my own case, the woodworm has had about 450 years to wreak havoc - and failed to do so - so I suspect I don't need to worry too much about some localised frass.