On 4 Jan, 14:09, RobertL wrote:
the Victorian house we recently bought, and which is empty while we
are doing it up, seems to have a lot of woodworm holes. *It's in floor
boards and joists. *The worst are some ground floor joists. *I know
that in heated hosues these infestations tend to die out but I cannot
tell whether this infestation is active or not. I plan to take
professional advice but....

I know (from *past experience) that most comanies require you to lift
floorboards every metre (and use a 1 metre spray nozzle). *I would
like to avoid lifting so many boards because of the damage. *Most of
my boards run right across from side to side so they are hard to lift
without either cutting the boards or removing the skirting boards.

Does anyone know a company which will treat an infestation (if
required) using longer (say 2m) nozzles, so I can lift fewer boards?

Many thanks,

Robert

Dear Robert
As Gerald so rightly observes the chances of your Victorian house
having active woodworm is remote. From the evidence I have
subjectively and slightly objectively (ie survey data of about 200
houses surveyed) assessed, I put the chances at between 1% and 5% at
the most. So what do you do? Firstly may I say that at this level of
risk the cost of treatment - say £1,000 by the time you have done all
the work - is a poor investment and is best off in unit trusts or
elsewhere.
I suggest you monitor the attack as follows: get some glue that does
not contain a biocide (flour and water?) and put on tissue paper to
all the affected parts you can get at PREFERABLY under the floor
boards and joist if some traps are available. Wait till Semtember
2011 (though not harm looking every September thereafter) and absent
any NEW flight holes through the paper you know the attack is dead.
Absent any ni Sept 2009 increases your chances of it being dead 100
fold but to be sure you have to wait 3 years!
All you then have is a structural problem to be assessed - such as
damaged sapwood on floorboard edges prone to high heels going through!
To answer your question - ie if YOU want to treat you would best be
advised to get a firm that does not understand fully the COSSH
regulation which require them not to treat unless it is active or
there is a risk of activity and which has access to a fogging machine
which will be used without lifting any floorboards. This normally uses
a boron-based active ingredient and access is obtained via the air
bricks. It is expensiver and in my opinion would be a complete waste
of money but you are the client so you decide. The idea of long
lances is not practical unless your oversite is very deep. Best to
lift two or three boards side by side to improve ange and access but
most firms do not have such flexibility.

Chris