A blog post

Lyctus Brunneus (no he’s not a Roman Gladiator!)

Posted on the 07 June, 2010 at 2:56 pm Written by in Case Studies, Powder Post Beetle

Powder Post Beetle Advice

It has become extremely popular over the past decade or so, to rip up those carpets, drive down to your local timber yard and purchase and lay that beautiful oak floor that you’ve always craved for!

Costs a lot of money, but hey………. it looks great, feels great and more importantly will last for years.

But hang on, what’s this…………. You start to notice little holes appearing in the floorboards, what can it be? Its woodworm, the little blighters have got into my new floor.

However the culprit in this particular case is unlikely to be your ordinary woodworm the Common Furniture Beetle (Anobium punctatum) as generally found in domestic housing, as well as period and commercial buildings, but is more likely to be Lyctus Brunneus, otherwise known as the Powder Post Beetle.

Powder Post Beetle following emergence from oak floor boarding

Powder Post Beetle following emergence from oak floor boarding

Powder Post Beetles are insects that attack the sapwood of wide pored hardwoods such as Oak & Elm and over the last 10 years or so we at Premier Heritage have investigated numerous cases of this particular insect. It seems to be becoming more frequent with reported cases most commonly in flooring, but also identified in new furniture, as well as structural and decorative oak timbers introduced during new build construction.

Powder Post Beetles attack the sapwood that has a sufficient starch content (greater than 3%) and it is evident therefore that it is a very specialised insect indeed and has very specific requirements, especially in relation to starch. Indeed, it is the starch content of potentially susceptible hardwoods which make them prone to attack by the Powder Post Beetle.

It should however be noted that as wood ages the starch content declines (due to bacterial action) and therefore after around 10 years or so, the levels will have dropped so that infestation/activity is no longer possible.

Furthermore, given the special requirements of the insect it is not going to infest the existing old hardwood timbers (if any) or those softwoods found in housing.

Given the very special requirements of the insect and the wood it attacks (newly converted wide pored hardwoods with sufficient starch content), then your normal domestic house will not contain such timbers, except where they have been introduced to form a new hardwood floor.

Powder Post Beetle

Powder Post Beetle damage to a newly laid oak floor













It is also extremely unlikely that this insect will fly into your property where such susceptible timbers have just been laid, but almost inevitable the insect would have been introduced with wood already infected; this occurs where such wood may have been stored, i.e. timber yards, furniture manufacturers etc.

What to do if you find Powder Post Beetle in an oak floor

If you find woodworm in your new Oak floor what should you do?

• Well firstly the infestation needs to be correctly identified; incorrect identification could result in unnecessary chemical treatments being applied and as such the floor should therefore be inspected by a qualified Timber Infestation Surveyor (CTIS or CSRT).

• Having identified that the infestation is the Powder Post Beetle then it should be considered that the flooring materials would almost certainly have been infested prior to purchase and being laid in your property. You should therefore consider taking the following initial action.

Contact and advise the contractor who laid the floor (this is with whom your contract would normally be formed) or the suppliers of the timber, that the flooring is infected by woodworm and as such should be considered ‘defective’ and not of merchantable quality.

Powder Post Beetle frass and beetle emergence holes

Powder Post Beetle frass and beetle emergence holes













If the wood is of aesthetic value then it may be argued that the damage (holes) make it not fit for its purpose. If one examines the wood and finds elongated surface scoring then this indicates that the damage was present when the wood was sawn and planed, i.e., long before you bought and laid it in your property.
You should then consider the following actions:

1] Ask for the wood to be replaced as it was supplied defective.
2] If the damage is very minor (on a few sapwood edges), then you could consider using an ‘injector’ to apply a wood preservative into the holes and this could be an acceptable solution. Nevertheless, inform the supplier of the problem and it may be prudent to put them ‘on notice’ that if the infestation should worsen then you will expect them to take appropriate action over it.

Note: Do not chemically spray the entire floor! Most floors retain some form of stain or varnish that would limit chemical uptake. Also treatment in most cases, to be fully effective, rely on chemical being applied to both sides, which after the floor is laid won’t be possible, and clearly to lift the floor would be very expensive, and almost certainly cause irreversible damage.
Finally, don’t let the supplier of the timber fob you off with the ……”It’s nothing to do with us mate – you’ve got woodworm”. Yes you have, but inevitably this insect was brought in to your home with the new hardwood, and it is therefore certainly the supplier’s problem.

some comments

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  1. Paula 10 August 2010 at 7:47 pm permalink

    What if you find the holes in the oak hardwood flooring just around the baseboards throughout the house (new house). What does that mean? We have the beetles flying around!