Help with Woodworm

Sexy_Legs

Hello everyone we need some help with getting rid of woodworm

The house is 1950 needing complete refurb.

We have noticed woodworm in floorboards in bathroom upstairs and downstairs in kitchen which is directly above effected area in bathroom upstairs.

We will get a specialist in, so will the whole house need to be done or just the affected area, also can anyone recommend a company that covers Newbury area and a rough indication of costs involved.

Thanks very much
D

dampdaveski

Hi sexy
You need to determine whether the infestation is active first
Do the holes look fresh? ie nice and clean inside
Is there bore dust around or underneath the holes (this will feel a bit gritty when rubbed between your fingers)
are there any adult beetles on the window cills or in the bath / sink? google woodworm beetle and there are loads of sites with pics on
IF it is proven to be active would probably be a case of getting the floors sprayed.
As for a company in Newbury check out the pca site www.proprerty-care.org site. Be wary of the national companies they pay their operatives, surveyors, area managers etc on commission / performance bonuses. Draw your own conclusions!
Hope this helps
DD

David_Aldred

Hi,
Woodworm (common furniture beetle) was estimated to be present in around 60-70% of the UK housing stock in the 1970’s so hence damage by this insect is as its name implies quite common. The PCA as Dampdaveski says will have a member contractor in your area and if proven to be active be aware that the beetles fly so the entire house is at risk.

The first thing to ask is have you actually got a LIVE common furniture beetle or its larva in your hand removed from the wood of concern? This would be unusual at this time of year because the adult beetle emerges from the wood (hence the circular holes you see where it bit its way out) from about late Spring to late Summer to breed, the female lays her eggs and then the adults die.

If you ask anyone round to your property to inspect the problem and they say the infestation is active then you should say “right then show me the LIVE beetle or larva from that wood”. If they cannot show you an actual live beetle and / or live larva from that wood you have just been told a pack of lies for the profit of the contractor at your expense and you have just caught out a cowboy specialist contractor. Such cowboys are on a sales pitch, treatment means a job for them, means the lads of their company are in work, and especially it often means another juicy commission for themselves as nothing more than a cowboy salesman. They give the chat as the specialist and you are the layperson with mug written on your forehead as far as they are concerned but in this case you will have done a bit of reading up on the subject so they better watch out.

First of all it is not true at all that because the holes are clean or that frass (bore dust) is present that the infestation is active. The holes can be clean for all sorts of reasons and old frass can be shaken out by traffic or anything close to the timber causing vibration. Pick a piece of inactive damaged timber up and shake out the frass – does that make it active? No of course not. It is like finding a hole in the ground and a stranger saying I bet there is a live fox down there – no actually it’s a hole, nothing more nothing less. If the cowboy attempts to show you a dead beetle as reason for treatment that is fine – it’s dead you’re not interested in dead ones, you are only interested in any live ones.

You can spray chemicals at holes until the cows come home and guess what the holes will still be there. How old is the house? How long have you been there? Do you think you are the first person to have seen this damage? Do you think you are the first person to have treated it? The holes are where the insect bit its way out to breed so it is an EXIT hole although a female beetle may lay her eggs down such or in end grain where it is easier to gain entry to the depth of the timber and somewhat sheltered.

What any competent surveyor should say is “I am sorry but at this time of year I cannot see any LIVE beetles or their larva and accordingly I cannot say whether or not that damage relates to an active or inactive infestation so my advice is for you to monitor the situation over the next twelve months and if proved to be active we will consider what the options are” to which you say “thank you for being so honest I will be in touch”. In practical terms as dampdaveski says if there are a lot of dead beetles on window cills and in the bath you should have a good idea that they only got there fairly recently so it is odds on you have an active infestation but as yet not a proven active infestation.

The use of long lasting chemical insecticides (and remember these are 30 year guarantees being issued so they are indeed long lasting) has to be justified under a good deal of legislation including Control of Substances Hazardous to Health (COSHH). Spraying holes in wood with long lasting chemical insecticides without first finding any LIVE beetles or larva consistent with common furniture beetle is not what you might call sufficient justification and unless a contractor can prove they are treating for live beetles being present they run the risk of being held liable for negligent advice and damage to your property.

This need for justification came about over raising concerns at the number of long lasting chemicals being thrown into houses such that the phrase ‘toxic box’ came into vogue. This was not just a general environmental issue but because there are many houses that were treated with these long lasting chemical insecticides that have now been banned after they were unfortunately shown to be unacceptably related to cancers. Not a comforting thought the next time you are kicking up all that dust in the loft space that may or may not have such chemicals mixed in with them.

The common furniture beetle are attracted to white bright surfaces when they emerge from the timber so they are often found upon window cills and white sanitary fittings so check these surfaces during the summer months. If you don’t know what these beetles look like then do a google image search. Also tape paper over wood with flight holes you are concerned might still have activity within as this will tend to trap or show signs of any emerging live beetles. Lay white wallpaper lining over the loft floor as this will attract the insects emerging in the closed void and there are also baited traps that will attract insects for monitoring purposes in confined spaces.

The most common (no pun intended) place to find common furniture beetle in a house is around the bathroom w.c. as without going into too greater detail this tends to be a wet area that makes the wood more palatable to the insect. Also the plywood of panelling / meter boards is often nicely palatable to the insects. If the meter board is infested the electrical company that owns the board will need to deal with this item.

Adult common furniture beetles fly such that the whole house is at risk if the infestation is proven active. However they are an insect of the forest and old dirty timber covered in soot and debris of a low moisture content within a house you can imagine is like you being offered dog food – you would eat it if you had to but if this is all the restaurant has to offer we’ll try somewhere else and hence the reason the insect is going to prefer new wood introduced compared to those old loft timbers and why much of what is seen to original timbers in older houses is inactive historic damage. That is not to say common furniture will not eat timber in your average house it’s just a question of preference for what is on the menu and why the insect prefers rural or semi rural houses to smog filled industrial areas.

There is also a claim that if timbers can be maintained with a moisture content below 12% the infestation will die out naturally and that this could be achieved with a centrally heated house. Whilst lower moisture contents will reduce activity it is not practical or possible to maintain such low moisture contents in all areas of the house throughout the year and common furniture will cope with reduced moisture contents over quite significant periods.

So let’s just say you actually find LIVE beetles or larva consistent with this common furniture beetle. What are your options? Well is that beetle from wood in your house or did it just fly in through your open window which they will often do. If however you have a few beetles on the window cills then it's not rocket science to work out what is going on and you better go looking at the house timbers.

As regards damaged wood you can rip out the effected timber and replace with pre-treated timber if the structural integrity is compromised or you just want to be rid of infested timber. If it is only one or two beetles flying about you could do nothing and think of it as a household pest and leave it to the beetle’s natural predators within the house to battle it out. If there are quite a few live beetles you may want to contemplate controlling the problem yourself or you may want to get somebody in to do it on your behalf.

If you or somebody you appoint sprays an insecticide you are going to kill the beetle’s natural predators along with the woodworm so that is not a particularly good start. Also you must appreciate that spraying or brushing insecticide is a surface treatment and not all areas can be reached / opened up to be treated and some are covered in paint varnish etc such that the treatment is only ever going to be partially effective.

The insecticide is only going to be effective on clean bare wood with an emphasis on the clean and the bare so attempting to spray dirty or coated timber is a waste of time and money. To even partially spray a loft void you would need to clear out all insulation, all debris and industrial vacuum all the surfaces prior to treating. If somebody is quoting you then if they include for this preperation work it will give you a measure for how competant they are. If they just step up into an insulated loft on their own without being monitored and spray the chemicals with the insulation / debris in place (or just turning it over as many do) you have just been ripped off as it will have been a waste of time and money plus they will have created an avoidable hazard in your house with all that fine debris up there now contaminated with insecticide for you to kick up and breathe in next time you or whoever are up there.

Unless of historic / special interest it is often more economic to replace with pre-treated timber any painted / varnished timber that is infested rather than attempt to remove / strip / clean and treat then re-fix. The contractors do not unless instructed otherwise allow for treating anything other than structural floors and roof timbers so any skirting etc that is infested is usually down to you or at additional cost.

Spraying insecticide only puts a coating of chemical on the surface of the clean bare wood that penetrates a few millimetres. It does not penetrate the full depth of the timber so it is not an instant kill of all the woodworm within the depth of that timber. This is important to appreciate because not only will contractors often fail to tell you this but it has several implications.

The first implication is if an egg was laid just before you sprayed insecticide and its larva burrows down into the timber it will carry on living quite happily unaffected by the insecticide and continuing to eat the wood for what may be around several years before it changes to a beetle and emerges to breed / comes into contact with your insecticide. This being the case what appears to be little damage at time of spraying may change during that period to being quite severe structural damage several years down the line when those insects finally emerge as a beetles and hit the insecticide.

However what may happen is that the beetles may avoid treated areas and instead emerge, (if at all), in areas that are untreated which may be timber joints. Such joints are a common site for infestation to occur and any treatment that tends to further concentrate attack in joint areas should obviously be avoided. Following treatment the client may see no new flight holes appear and the problem may be thought to be under control but may actually be continuing where it cannot be observed / checked.

So the contractor is not usually going to want to entertain re-treating for around seven years after initial treatment because any woodworm beetles you continue to see during that time they will say are due to the fly out period and the amount you see should diminish over time if the treatment has been adequate to break the breeding cycle.

But what if you still keep seeing woodworm beetles after seven years? Well if the contractor is still in business you can recall them usually for a fee. A common defence is they say - well we did not treat every bit of wood in this house so you prove to us (the contractor) that a live beetle has emerged from timber we have treated and we will consider re-treatment.

This as you might imagine is no easy thing for you as a layperson to do and you still have to prove their product of insecticide is on that particular piece of timber with live insects in it. That means sending samples off to an independent laboratory at considerable cost and the lab doing a targeted analysis for that particular product being present on that particular piece of timber so as there are many different chemicals used you need to know what is in the specific one the contractor used before you can fund the lab work.

If you treat the area yourself with woodworm killer from a DIY store or builder’s merchants it is often Permethrin based which does just as good a job of killing the insect as the products many contractors use. It will be an awful lot cheaper than a contractor to treat the timber yourself but you won’t get a long term guarantee for what that is worth and spraying chemicals in confined spaces is not the best job in the world, especially for an amateur when there are considerable health and safety issues to be considered. Contractors who are Property Care Association Members should be fully trained in the safe handling, storage and use of these chemicals so this would be the first place to look for a competent contractor, though membership is no guarantee a cowboy hasn’t slipped through.

There are other methods of treatment such as smoke treatments, gas fumigation and heat sterilization. In addition small items that would be a problem to strip and treat such as picture frames are sometimes placed in a freezer to kill the insects within them without resorting to chemicals.

Contractors using insecticides should issue the client and anyone else who could be affected by the work with full and complete health and safety written instructions prior to treatment and fix warning notices during and after treatment. The work may be subject to the Party Wall Act.

Permanent notices after treatment stating who treated the area (including address and telephone number), date of treatment / product used / manufacturer (including address and telephone number) should be fixed in a prominent position to advise anyone entering a treatment area of the potential hazard.

No persons other than the person treating the timbers and those charged with monitoring them in a confined space should be present within the property during treatment and after treatment until the recommended number of hours has passed as set by the product manufacturer. Special considerations are required for protection of services, water tanks, animals, persons especially at risk etc and the manufacturer’s instructions and guidance should be strictly adhered to.

Hope this helps, kindest regards, David Aldred Independent damp and timber surveyor

dampdaveski

David,
have you worn your fingers down to stumps since you joined this forum?
Good advice though
DD

michaels

David - Thanks, post of the month for me and should be a sticky.

Sexy_Legs

David

Just to say a big thank you for your wonderful informative post, it has been a great help and hubby is going to re-read again this weekend so he can resolve problem.

Thanks

D