Home Woodworm in a Building Questions and Answers
Woodworm in Buildings

Anyone thought of a woodworm trap?

Q Someone should come up with a sacrificial material which would attract Common Furniture Beetle to reduce infestations. I suppose one of those Blue lights used to electrocute flying insects in restaurants etc. could have a similar effect.

A What you suggest has already been invented. They were pheromone traps which attracted Common Furniture Beetle for them to be 'caught' by a sticky lethal lure. They never really caught on, only had a limited life and a limited area of efficacy. We believe that pheromone traps are still available for other types of insects and are used for pest control. The flying insect traps are of little value for Common Furniture Beetle who prefers to crawl! If you invent something let us know!


Can you hear woodworm?

Q Can you hear woodworm? I can hear what sounds like a crisp packet being slightly crumpled in our loft space this has only just started now the weather has warmed slightly. Could this be woodworm?

A In the UK there are two types of woodworm that you can 'hear'. Death watch beetle (attacks decaying oak) and House Longhorn Beetle (attacks softwood in SE England - especially in Surrey). The most audible would be a faint scratching noise - not what you described. Could it be squirrels? Mice? Birds? Bats?


Potential woodworm - Potential damp?

Q We are in the process of selling our 2nd floor maisonette. However, our buyer's survey has shown up potential damp and woodworm problems (the property is approx 170 yrs old). The only sign of damp we have is mildew on the ceiling above our shower (which is located downstairs), no tidemarks or furry areas.  These problems were not picked up when we bought the property only 2 years ago. Is this something we should be worried about and would it be costly to fix?

A You state the purchaser's survey suggested 'potential' damp and woodworm. Potential does not mean it is there - it could be the surveyor is just covering himself. Is it costly? - How long is a piece of string? Impossible for us to say but if you bought it two years ago and had it surveyed then, it is unlikely that there is a serious problem if at all.


Woodworm in yard broom

Q Recently discovered a Wooden Yard Broom in my garage absolutely covered in active woodworm holes (they were not there last August). My concern is that next to this broom is a stack of Chipboard Loft panels which I am intending to put in the loft as soon as it gets warmer. They have been there since July last year. I normally treat all timber I use with a preservative but not chipboard and MDF.  My concern is the emerging beetles will have laid eggs which obviously I do not want to transport into my loft. Am I correct in thinking that unlike Plywood, Chipboard and MDF will not support woodworm? If this is correct how long should I delay putting the panels in my loft to ensure any eggs that may have been deposited on them have died.
A In 35 years I have never seen woodworm (common furniture beetle (CFB)) in chip board and I have also consulted with a colleague whose experience is similar to my own. We believe the glues used make it unattractive for egg laying so your risk is very small indeed. As the CFB lifecycle is three/four years you would have to wait this long to see if the panels have been infested but if I were you I would just lay it - there was probably much more attractive unadulterated wood to infest in your garage!


Is fogging any good?

Q I have just been quoted an extra £700 for 'fogging' (for woodworm) and the removal of a small area of wet rot under a floor, which was discovered during a treatment for rising damp (for which I have a separate quote). This will involve replacing a couple of joists. Do you think this is reasonable?
A You do not state the size of the areas that will be 'fogged' for woodworm thus it is difficult to say if it is value for money. Irrespective of this we are not great believers in fogging or micro spraying as an application method for treating timber against wood boring beetle infestation. Using this process it is difficult to achieve the correct amount of 'loading' of insecticide onto all surfaces of the timber. It is a bit of a gimmick used by some who actually fog a very weak Boric Acid formulation which has no contact killing properties and its effectiveness is reliant upon ingestion. Far better to have a persistent contact contact killer (Permethrin) sprayed but only if it is really necessary and has been fully justified.
How big is the area in question/size and type of house (e.g. 3 bed semi?) and is the wet rot a couple of 2"x4" joist ends? Have a look at the ''Treatment Guidance' section of our web site which should be of help to you.


Woodworm guarantee but no report - What to do?

Q I have recently purchased a house which has a 30 year guarantee for woodworm treatment which was issued in 1994. The contractor who issued the guarantee has subsequently been taken over by another company. The successor company say they will not honour the guarantee in the event of a claim (none has yet arisen) unless the survey report is also produced - and this is a condition in the guarantee. There is no survey report and it would appear therefore that the guarantee is worthless. What options are available to me in these circumstances?
A It is a requirement of most guarantees that in the event of a claim situation arising it is necessary to produce the report to which the guarantee relates. If the guarantee is being dealt with by a third party due to the original contractor having ceased trading then even more documents are required but these would be itemised on the guarantee document.

A guarantee document basically means that work of some type has gone on somewhere in the property. It is the report that explains what work was undertaken where in the property and what other conditions relevant to the contract were/are applicable to the contract. Sadly many solicitors are fixated on the guarantee document only and do not bother to read its conditions to ensure that their client is in possession of all of the necessary documents in the event of a claim situation arising. Some have argued that this is negligence on the part of the solicitor and we are aware of one case where a solicitor agreed to meet the cost of further treatment because they did not obtain all of the necessary documents to enable their clients to make a claim on the guarantee.

To summarise therefore if you do not have the original report and other documents stipulated in the conditions of the guarantee then it is unlikely that you will be able to enforce the guarantee. In your case however if the company was taken over then it is likely that the completed works records still exist. Explain that there is nothing wrong and no need to claim but you just want to assemble all of the relevant paperwork - better still get your solicitor to do it!


Woodworm in oak roof trusses and ply - Advice please

Q We are renovating a barn - all the old timber has been removed and destroyed.  We have installed European green oak trusses and 16 oak purlins. The oak showed no signs of woodworm when it was put in.  Two weeks ago we installed far eastern plywood into the door sleeves. Last week we noticed small holes in the plywood. The importer has said that this is pin worm and is dead. We then noticed what very much looks like woodworm in the purlins and the 2 king trusses. The oak was stored on pallets on our lawn for four weeks before being made into trusses. It was covered up from the effects of UV. We are receiving conflicting info on whether it is likely to be woodworm brought in via the oak or the plywood. Please advise?

A Though we cannot be certain, it is likely that the infestation in the far eastern plywood is caused by a different insect to that which is present in your oak roof trusses and purlins. Also we have never heard of 'pin worm'? There is a beetle called pin hole borer but it would not be in ply.

A very common pest of European green oak is Powder Post Beetle (Lyctus brunneus). One way to identify if it is powder post beetle is to rub the bore dust dislodged from the holes in the timber between your fingers and it will feel talc-like. The lifecycle for powder post beetle is 1-2 years outdoors or 8-10 months indoors. This should give you an indication as to the origin of the infestation since the exit holes that you now see would have taken either up to 2 years or 10 months to be formed. It is a pest of timber yards and hardwood stores, thus it is not unusual that the infestation originates from storage areas prior to introduction. Subject to how long you have owned the wood, you could in theory now reject it since it is not fit for purpose, but in view of the fact that they are now important roofing timbers this course of action is very likely not practical. If the wood is bare and not coated with anything that will prevent the penetration of a surface applied preservative then we would suggest that all of the exposed timber surfaces be treated with a 0.2% ready-to-use Permethrin based material.


Can I blame my neighbours for their woodworm shed?

Q My neighbour's shed is riddled with woodworm and is being dismantled. It is attached to my decking and my decking gate, which appears to be soft under foot.  Has the woodworm spread? I often find "beetles" downstairs in my house, is this wood worm beetles? Would my neighbour be responsible or not?  They've known about the shed for years.

A Your neighbour's shed probably has nothing to do with your decking. Woodworm are abundant in nature so it is not possible to point to a single infested item and to blame that or its owner. Have you not treated or protected your decking with a preservative? If you have not then you only have yourself to blame. Impossible for us to comment on the beetles without seeing them.

How do I treat Powder Post Beetle?

Q How do I go about treating Lyctus Brunneus (powder post beetle)? Who do I contact to do the job?

A Lyctus, often referred to as powder post beetle is a pest of the stock yard infesting wide pored hardwoods, predominantly oak. The wood has to be relatively new since the starch content on which it relies diminishes naturally ten to twelve years after felling. After this time it is not able to survive or infest timber. It is often found in hardwood floors and furniture each of which present their own difficulties for treatment due to painted or varnished surfaces, construction methods and secret fixing.

If the infested timber is less than twelve months old you should reject it under the sale of goods act as it would have been infested at the time of purchase. If it is more than twelve months and less than two years you could still try rejecting it but because of the length of life cycle you could be on thin ice. If treatment is necessary then a contact killing insecticide containing 0.2% Permethrin should be applied to all timber surfaces - no varnish - no paint. Who you contact

Are these prices fair?

Q We are in the process of buying a 1900 Victorian end terraced house and had a damp and timber survey done at no cost. We have had the report back and it doesn't sound too good. Tests showed high levels of internal dampness on the front bay window, gable wall of front room, areas of both internal/external walls of the rear room and all walls in the kitchen. As well as wet rot in the front room, he also picked up on the kitchen floor having felt damp proof course which is hiding problems. He has quoted us on damp proofing which is: £612.00 to insert chemical damp proof course to ground floor walls, £1,416.00 - remove/replace the complete living room floor, £75.00 - provide guarantee cover for rising damp, £75.00 - guarantee cover for timber treatment which in total is £2,178. As we know nothing about this sort of area is this a fare price? Also do you think companies that do free surveys add on extra costs?? Is there a cheaper way of doing this? Please help, we need your advice! Thanks

A You will have read on our site that we are not able to comment upon individual prices quoted since we have not seen the property.
You should certainly get more than one opinion - three at least. Try to get Property Care Association members and a CSRT qualified surveyor. You do not say if the price to inject a new DPC includes replastering. If not what have they said about the replastering which would be essential? We do not understand what you are saying about the kitchen floor. What is the original DPC? Did they not discover? The guarantee prices that you quote seem expensive.

Free surveys are always speculative and they naturally will be enthusiastic in their diagnosis and remedy since this is how they earn their living. Independent surveys and opinions such as those provided by me often save money as they often avoid unnecessary work. Whatever faults are found in the property should be negotiated off of the asking price or your offer price. You are quite at liberty to re adjust your offer based upon the cost of work necessary - this is usual. A sensible option is to engage the services of an independent specialist surveyor who does not have a vested interest in what is found. More often than not this saves money. You should also read our 'Getting on with the job' manual which may be downloaded from our web site as it will be very useful for you.


Does central heating prevent woodworm?

Q I have been told that if a house has central heating that is keeping a house warm continuously, wood worm are unable to survive. Is this true?

A What you say has been circulated and we understand that this suggestion was based upon very limited research and dare we say without much thought. It is true that dry wood is less susceptible to wood boring beetle attack but it is not possible to achieve this continuously in a normal property. The only timbers in a property that benefit from central heating are those forming the upper floors - but central heating is only on for 4 to 5 months of the year and even then not for 24 hours a day. So what about the other 7/8 months?

Those timbers forming the ground floor receive no heat and hopefully should be exposed to good sub floor ventilation. Those forming the roof structure are above the insulation and should therefore not benefit from the heat in the property. Also in a roof void there should be good ventilation to prevent condensation forming which would make the timber damp and more prone to an attack!

It must have been a comment made by someone in the past who basically had not thought through what they were saying.


Can I treat this myself?

Q I have recently bought a small one bedroom flat that had previously been completely gutted and fitted with damp proofing. After successfully overcoming all the problems renovation will usually throw at you I have come across a section of the joists that are damp and have evidence of woodworm. The holes are small so I would think they are from a weevil rather than beetle. Does anyone know if it will need professional treatment or if I can fix the problem myself? Also how much will it cost? The affected area seems to be concealed within the bathroom which is 4 x 3 M sq. The boards are bare here but I have had the rest of the flat sanded and sealed.

A You state the flat was 'gutted'. Did it have complete new floors therefore or are they original? There is no reason why you should not treat it yourself. All you need to know is on this website under the ''Treatment Guidance' section.


Damp and timber inspection required but it is already guaranteed?

Q I'm currently moving home and my current house has a 30yr guarantee for damp and timber that has 19 years left to run. The purchaser's mortgage adviser has asked for a damp and timber report. Why is this if the guarantee is still valid?
A This is not unusual but you should query this with your purchasers. Did their surveyor find a problem or is it just a routine request? They might not know that guarantees already exist. If it is necessary only get the company responsible for the guarantee to carry out the check and it is likely they will charge which is perfectly reasonable. It is not ethical to ask another company to check another company's work but if they do then it is almost certain they will find something wrong and rock the boat!


Should council pay for woodworm treatment?

Q We recently bought our house from the council, a three bedroom semi detached. We knew from the building survey report there was active woodworm in the roof rafters. We informed the council, however because there was a 'right to buy' purchase order on the house they didn't come out to inspect. We recently got a quote for £300+VAT to treat the entire roof from an approved timber preservation contractor.
A To answer your questions in the order raised:

1. Whether or not the council should pay for the cost of treatment would depend upon the agreement, if any, that formed part of the contract when you purchased the property. We know that some of these "right to buy" schemes incorporated a 12 month "defect discovery period" during which time the council would pay for any essential repairs. If no such agreement exists then caveat emptor (buyer beware) would apply and the costs would be down to you.

2. To the best of our knowledge no building fabric insurer covers against woodworm infestation.

3. It would most certainly be cheaper if you carried out all of the preparatory work in the roof void prior to it being sprayed. Whether or not you want to do this would depend upon the type of insulation material present as it may be possible for the treatment contractor to hold this back from the ceiling joists with a stick, apply the treatment and let it fall back for minimal cost and save you the bother of removing it. A completely empty, fully prepared roof void over a 3 bedroom semi should take approximately one hour to spray and would consume approximately 50 litres of fluid. The cost of a standard woodworm fluid to a contractor for this would be around £20-£30, the remainder being labour charges. We hope that the above information is of assistance to you.


Is woodworm dust dangerous?

Q We have been working in house that it is covered in woodworm and when you bang or cut the timber the air is full of the woodworm dust and when breathe in it makes our nose hurt. Is this a problem?
A All dust is a hazard and if you are working in a dusty environment then you should be wearing a suitable mask to reduce the risk it poses. The bore dust/frass generated by 'woodworm' does not as far as we are aware pose any greater significant risk - just wear a suitable dust mask.


Italian Longhorn beetle - help please!

Q We moved to Umbria Italy a year ago and had an old house completely restored. We now find that some of the new beams ("Rovere" = English Oak) are infested with il Capricorno - Hylotrupes bajulus the Old House Borer. We have several holes, have found an adult dead, and are living with the cheerful chirping overhead in the 300x250mm beams, which are exposed as is common in Italian architecture. Some of the diagonal beams are double thickness - one laid over the other. We are starting to get estimates and advice. Today's suggestion was Dichlorvos mixed with cipermethrin and dimethrin injected by syringe, under pressure and nebulised through the house. We should leave all contents of the house as they are, except for any food or food containers, and vacate the house for the 2 days of work plus 3 days of toxicity. I would really appreciate some advice here. I understand that penetration is of paramount importance, but wonder if this is the best product. I have read about boron derivatives, and wonder if these are better. So if you can provide information on best products, method of delivery, advice re toxicity avoidance and realistic expectations for efficacy, I would be most grateful.

A Thank you for your 'jam packed' question!
Naturally we are not familiar with wood borers or the legislation applicable to the use of pesticides in Italy but we will try to answer some of your queries.

You state the new beams are 'Rovere', which we understand to be Italian oak. You then state that you believe some of them to be infested with Hylotrupes bajulus which in the UK is called House Longhorn Beetle. Longhorn Beetles are of the family Cerambycidae which is a family of beetles of about 20,000 named species. What is strange is that Hylotrupes is a pest of softwood - not hardwood so we would question the identification you have had.

You mention Dichlorovos which is classified by the W.H.O. as class 1B 'highly hazardous'. It is a hazardous organophosphate highly toxic by inhalation, dermal absorption and ingestion. It would most certainly not be used over here any more. You then go on to mention the possible use of a 'cocktail' of pesticides being used together an even possibly 'fogging' them. Treatment of timber should be 'targeted' in order to achieve adequate 'loadings' of the active ingredients and fogging does not achieve this - it also contaminates all surfaces which should be avoided.

For insects such as Hylotrupes bajulus we would advise the high pressure injection of the timber with a solvent based insecticide via one way valve timber injectors inserted into the timber at the appropriate centres. You may wish to leave the injector nipples in place for future 'top up' treatment. Because of the size of the insect one needs to use a material that will achieve a high initial kill rate and this is one of the rare occasions that justifies the use of a solvent based insecticide which should contain 0.2% Permethrin which is an efficient contact killing insecticide. It is also known that the solvent vapours have a significant 'kill' effect hence its use is justified.

It is important that all of the timber surfaces are adequately coated. Any varnish or polish would have to be removed before treatment. Some of the larvae will be at depths greater than the insecticide will reach so expect continued activity for some time but eventually you should win!

Borate is a stomach poison so the grub would have to ingest it for it to work. Tests have shown that they avoid it rather than eat it so they eventually die, but this is a long process and it sounds like you need something that will act more quickly.

Hope the above is of some assistance to you.


Two different opinions

Q I am in the process of buying a house and to be safe decided to have a damp proof and timber check done. I had one recommended by the estate agent who has done a lot of work for properties who I cannot find registered anywhere. I had one also done by the damp proofers who I have used before who is registered. My dilemma is that the registered one brought back a lot of problems so I told the estate agent so we could perhaps get some cost off the property. I did show them the report. The registered one brought up as well as damp that the timbers under the room and hallway had partly been replaced and bolted with copper coating at the end but that no damp-proofing between them and the masonry. So the estate agent sent in the unregistered (I think) to check and he says they are fine. Please can you advise as one says fine and the other has totalled to £1,500 so far which is a lot for me to have to pay out? Please can you advise?

A You say that one firm is registered and the other is not? Registered with whom? Please explain. You are right to be cautious however and this is why I offer an independent survey service. Obviously it is in the estate agents interest for there to be as little wrong as possible but it is also possible that the firm they put in has been negligent in which case you could have a case against them if you purchased relying on their survey but this is a lot of hassle you could do without. Why don't you arrange to meet the 'registered' company at the property and ask them to point out to you (perhaps accompanied) exactly what they have found. If they refuse or play awkward you may draw your own conclusions. We would also suggest that you arrange for a third opinion form a company who is a member of the Property Care Association and make certain that the surveyor is CSRT qualified. Look again at our web site and read Articles 4a - 4d inclusive You should find it very useful. Good luck.


Woodworm in my 600 year old house

Q Many oak timbers in my 600 year old house have visible external woodworm damage. I have pushed a sharp-pointed knife into these timbers; except in one, the maximum penetration is around 3mm. One spot only was around 15mm. I am told that common woodworm bores along and below the surface rather than deep into old oak. Is this true, in which case we should treat the timbers with Rentokil or similar but not worry about the structural integrity of these timbers? Needless to say, treatment companies have assured us expensive treatment is required!

A 600 year old oak timbers are unlikely to be infested by active wood boring beetle infestation unless some form of fungal decay is also present. In such timber it is usually only the sap wood that was once infested, the heart wood, which usually forms the bulk of the section, remains unaffected. In fact you would probably burn out a drill attempting to drill a hole into it! The nutritional content of such old sap wood is now very diminished making it unattractive to a new infestation. It would almost certainly have been 'treated' several times in the past and it has survived 600 years - the majority of this time would have been without any preservative treatment at all! The historic woodworm holes and damage of the sapwood will remain for ever - some would call this character, others would try to make this a reason to carry out what would almost certainly be unnecessary treatment.

I have made these comments without sight of the timbers and there is always the exception to the rule. If  Death-watch beetle is present and active then remedial action would be necessary and the structural integrity of the timbers affected would need to be ascertained. The bottom line is what you would need to do - or not to do - that what would make you feel comfortable.

Let me know what you decide. Should you want to apply treatment please ask as there are other treatments available than those present in DIY outlets.


Italian woodworm

Q Following on from the question about the Italian boring insect, I have a similar story insofar that we bought a stone built property (about 100 years old) early last year in Northern Italy which had already been renovated. By the spring we realised that we have an active infestation (fresh holes and frass) but have had a very frustrating time getting quotes and advice in general. The only company that seems plausible has proposed a hot air heat treatment (up to 70°) as an injection treatment would, according to them, affect the structural stability of the property. The entire house has exposed beam and terra cotta tile ceilings. However, the costs seem excessive - about 10,000 Euro. As I am pregnant I am more in favour of this type of treatment as opposed to using an insecticide but wondered if the heat treatment proposed will be really effective. They have identified a mixture of the common woodworm and the Longhorn beetle based on visual assessment and using some type of electronic probe on the beams. Given the virulence of the latter I feel we need to deal with the problem as soon as possible and so am reluctant to wait. I am also amazed that none of the companies contacted offer any form of guarantee except the one mentioned, but even there it is only for 5 years which seems far too short if we have to fork out a similar amount of money to do the whole thing again in five or six years time.

A Heat treatment, whilst being effective if correctly executed, offers no long term residual protection. It kills everything present but does nothing to prevent further infestations. We do not understand how 'injection' would affect the stability of the property? Perhaps they do not do it so this is their counter arguement? We would go for treating the wood. Not knowing how large the property is it may be more cost effective to use a UK company to go out there and treat it - worth considering? Modern UK approved timber preservative insecticides present very little hazard and you are able to re enter a treated property after one hour. Just make certain that the working strength of the ready to use material (once diluted with water) is 0.2% Permethrin and not 0.1%. Good luck


Woodworm in the roof - Is it in the floors?

Q I am in the process of buying a top floor flat. I have asked an inspection of the roof for woodworm. I have just received the result it says: 'The timber revealed evidence of an infestation by the common furniture beetle, Anobium Punctatum, to ceiling and joists and roof rafters'. So a proper treatment will be carried out. Regarding this result should I ask an inspection of the floors as well, although the present owner told that a treatment was done 4 years ago, is it possible that the infestation has spread to the floor?

A With regard to the inspection of the roof is there any documentary evidence (guarantees, previous reports etc.) to suggest that the roof may have been treated in the past? There may be 'evidence' of an infestation but is it definitely active?

Why did you just have the roof inspected? If your surveyor noted the 'evidence' then the chances are that previous owners before also saw the same evidence and did something about it. If it does need treating get your solicitor to check who is responsible for doing this. There is a very good chance that the cost would be shared between the numbers of flats in the block - check the lease.

With regard to the floors if the present owner has told you that they were treated four years ago then he should be able to produce the report, estimate, receipted invoice and guarantee to prove this. If a 'friend' did it or he did it himself then he has wasted his time and money and you should proceed as if no treatment has taken place at all and request that the floors are inspected. If the floors have been professionally treated then it should be impossible for any new infestations to occur in the floors for at least twenty years irrespective of whether or not an active infestation is present in the roof. Hope the above is of use to you


Is mist treatment (fogging) effective?

Q The hall in our bungalow is badly infested with common furniture beetle. This will be treated with boron and the floor replaced but my concern is the other rooms. Is the suggested treatment applied in mist form from the outside of the house through the air vents likely to be effective?

A You state that the hall floor will be replaced and that it will also be treated with Boron? If it is being replaced then we would recommend that pre-treated timber is used and there would then be no need to carry out any treatment on site apart from cut timber ends. If on the other hand if the floorboards are to be replaced and the sub-floor joists and plates are to remain then these would need treating. If the boards are up then sub-floor timbers should be spray treated with a Permethrin based insecticide at a working strength of 0.2%.

You are right to be concerned about the other suspended timber floors in the other rooms. Beneath the floor there will be little obstruction to prevent the spread of a common furniture beetle infestation. It is almost certain that if a badly infested hall floor has been identified to the extent that timber renewal is necessary then there is a very high chance that an infestation is present in all floors. Wood boring insects do not stop because there are doors and partition walls on top of the floor. Beneath the floor as mentioned previously little obstruction is present. It is also worth pointing out that the climate beneath your floors is obviously conducive to wood boring insect attack and perhaps the timbers have a slightly increased moisture content, which wood boring insects will like, due to poor sub-floor ventilation. Consider significantly improving the sub-floor ventilation so as to change the sub-floor climate. Some refer to this as 'environmental control'.

In your question you query the effectiveness of applying a borate (boron) based preservative by fogging/misting it through the air vents. Let us first deal with a borate preservative for wood boring insect control. Disodium octoborate, as it is known, is what is known as a preventative form of treatment rather than curative. This is because disodium octoborate does not have any insect 'contact' killing properties - it works as a stomach poison and therefore has to be ingested for it to be effective. It is possible therefore for an adult wood boring insect to emerge through a 'boron' treated surface and survive since the adult does not 'eat' any wood and no contact killing properties are present. It will therefore 'prevent' future infestation if the correct loading (the amount of borate) is present in the surface of the timber. This is because the larval stage of the insect has to 'eat' its way into the timber and in so doing it will ingest the material. Permethrin on the other hand is a preventative preservative as it has contact killing properties. Adults should not be able to exit through a treated surface or die shortly after as they would have come into contact with the material.

There has been much debate about fogging/misting as a means of applying a timber preservative and boric acid (a form of borate) is one of the materials known to be applied this way. Curcumin is a yellow coloured material that reacts with 'boron' by turning a red/orange colour. It takes a tiny amount of 'boron' for this reaction to take place. Some use Curcumin coated sticks as a colour reagent test to prove that the mist/fog has reached all areas which looks very impressive but be careful. All preservatives by law have what is termed 'Statutory Conditions Relating to Use' and labelling that contains application rates. It takes a huge amount of time to achieve the prescribed application rate by fogging/misting so in the real world does this happen? With regard to fogging/misting what has never been questioned is the distribution of the fog/mist but what has been questioned is the quantity or loading of the active ingredient in the surface of the timber for it to be effective.

I am aware that some companies will propose to fog either through air vents or by raising one board with floor coverings and furniture remaining in place. This is obviously an attractive proposition as it minimises the amount of upheaval required. It is important to note however that this method will leave the whole top surface of the floor boards without any protection at all and we would not be happy with that. Stripping a room back to the boards and raising them for conventional spray treatment is the only real way to assess the degree of infestation present otherwise how will you know?

For more information on fogging/misting return to our website and follow the link to Graham Coleman's web site where he has an article on the subject. It may be tempting to go down the fogging route to minimise disruption but for efficacy I would recommend the spray application of a 0.2% Permethrin based insecticide.


Sorry for rambling on but hope that the information is of use to you


When to treat woodworm?

Q What is the best time of year to treat wood worm? We had a job done this week and somebody informed me that this was the wrong time of the year to do same.
A There is no 'wrong time' to treat woodworm (Common Furniture Beetle) because of the persistent nature of the treatment materials. In fact now (March) is a good time since they emerge between May and September so you will exterminate this season's generation.


How much should timber treatment cost?

How much should it cost?

We are frequently is asked is 'How much should it cost' to carry out different types of remedial treatment in a property. Experience shows us that there are regional variations but we also know that there are sometimes enormous differences between companies quoting for the same work. It is important in these circumstances to very carefully compare who is quoting for what and who is omitting some aspects of the work that others may be including. If you go to the articles section of this site and read Articles 4a - 4d inclusive we hope you will be better informed.

Larger organisations obviously have greater overheads than a sole trader and logically one would think this should influence prices but it is not always the case. So what is a reasonable price?

The price a contractor charges is usually made up of two elements: 1) The labour charge which normally includes all overheads etc. and 2) costs specific to the job such as materials, plant hire, rubbish clearance etc. Outlined below are three different trading styles for three different types of contractor:


1. The organised sole trader

Let us look at a sole trader who rents a small yard employing a labourer and his wife on a part time basis. He wants to earn £30K per annum, his labourer £17K and his wife £10K. If we now factor in all overhead costs associated with running such a business over a twelve month period a figure in the region of £85K would need to be generated for this type of business just to stand still.

If we now deduct holidays, bank holidays, illness provision etc this leaves our organised sole trader 44 working weeks to generate £85K. Divide £85K by 44 weeks and he needs to earn £1931 per week. Divide this number by 5 and he needs to earn £386 per day. It is important to remember however that this is just the 'labour only' element of the job. The cost of materials, rubbish clearance, plant hire etc. specific to the job would be in addition to this figure.


2. The less organised sole trader

If we now look at a contractor who works on his own form home with no yard, wanting to earn £25K per annum, cutting back on certain overheads and targeting to work 46 weeks in a year. He would need to generate somewhere in the region of £35K per annum in labour costs to achieve this. On this basis a day rate of £152 would be necessary plus materials.


3. The small organised company with four vans

Finally if we now look at a small organised company with a director/surveyor, one other surveyor, 2 office staff, five operatives and four vans. This company would need to generate £365K per annum in labour costs. However because the company has four working vans the day rate requirement would be somewhere in the region of £400 - surprisingly not too dissimilar to the organised sole trader in 1 above.


Timber preservatives and rising damp treatment fluids and creams are relatively speaking not very expensive. Cellar conversion work using membranes, sumps and pumps does have higher material cost content. To gain an approximate idea of how much a job might cost therefore depends how many man/van days the job will take plus material costs. There is no industry set price per meter run of wall or square meter of surface to be treated.



Is it necessary to remove everything to treat?

Q Is it possible to treat the whole house for woodworm without removing everything in it?

A Yes it is possible to treat the whole of a house for woodworm without removing everything but it would have to undertaken over two or three stages. It is essential that all floor coverings are completely removed - there is no way around this. Single large items could remain in rooms such as a dining table or wardrobe. To create two stages for treatment divide the house in two by moving things from front to back or visa versa to avoid moving having to move things up and down stairs. The contracts manager of a treatment company should advise you what to do.

There are some companies who offer to 'fog' or 'micro spray' and do not require rooms to be emptied. In my opinion such treatment is very limited and it is questionable how effective it is. Hope this helps


Bright yellow/orange powder?

Q I have spotted a small pile of fine bright yellow/orange powder that seems to be falling from a gap in some vertical cedar singles on the side of my roof balcony that was constructed about 2 years ago. (I live in Hertfordshire) Could this be bore dust and if so what is the likely type of woodworm present and what is the best treatment? The cedar shingles are nailed to treated softwood battens that are fixed to plywood on softwood studs. It is possible that rainwater may have got into the ends of some of the battens. I would be very grateful for any advice that you can give me.

A Cedar is naturally durable and resistant to wood boring insects. Without seeing the dust it would be impossible to say what the likely to be responsible for this. It is possible to identify most wood boring insects by the frass (bore dust) they generate as it contains distinct shaped pellets or is talc like. It may just be saw dust left from the construction.

Get a timber infestation specialist along who is CSRT or CTIS qualified. Make sure he brings his BRE identification book and a magnifying glass with him!

Contact Peter: Email - info@dampdecay.co.uk - Telephone: 015242 71794