Powder Post Beetle Habitat:-
Sapwood of tropical and European Hardwoods, principally oak and elm containing large pores and a high starch content. Not found in softwoods. Commonly found in new furniture, wood block and strip flooring. Panel products such as veneers, plywood and block board can be susceptible.
Powder Post Beetle Damage Characteristics:-
Emergence Holes – Circular in shape 1-2mm diameter 
Bore Tunnels – 1-2mm diameter usually running parallel to the grain. The sapwood is often completely disintegrated, leaving just a thin, intact surface skin of wood.
Bore Dust / Frass – Cream coloured, fine talcum powder consistency when rubbed between fingers. Will accumulate in small piles beneath emergence holes and can be easily shaken from bore tunnels.
Larvae – Up to 6mm in length, curved pale cream in colour; three pairs small legs, darker spots (breathing pores) on either side near rear of body. Found all year round in infested timbers feeding on the sapwood.
Adult Beetle – 4-7mm long, reddish brown to black; flattened and elongated with roughly parallel sides. Powder post can fly well and are generally attracted to light at night. Female beetles can lay up to 200 eggs and adult beetles can often been seen emerging from infected timber, making them easy for collection and correct identification.
Emergence Period – Found on or around damaged timber, particularly between May and September, although can be found all year round in heated building. It is evident with the Powder Post Beetle that environmental conditions and the nutritional condition and type of timber will much influence the length of their life cycle.
Powder Post Beetle Remedial Treatment:-
Targeted Treatments; – Organic solvent based chemical or pastes applied where sapwood is easily accessible. Treatment of floors and furniture rarely justifiable on the basis of cost, but more importantly treatments often ineffective due to applied finishes preventing chemical uptake. If you suspect you have a Powder Post Beetle problem and require specialist advice please call 0800 0 199 211
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 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 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
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.
Premier Heritage has recently completed timber and damp surveys of the Victorian canopies over the platforms at 2 of the busiest railway stations on the main line linking London with the West Country.
Platform 3 at Salisbury Station that has recently been given listed status by English Heritage.
These structures which date back as far as the 1830’s provide weather protection for the main platforms and waiting passengers, and are supported on a series of cast iron stanchions and steel trusses. The structural timbers forming the canopies are of pine and underclad with tongue and grooved pine boarding.
One of the complicated Salisbury roof trusses on platforms 2 & 3.
Planned maintenance and proposed new roof coverings called for a full condition survey of the structural timbers to be undertaken. This would determine any timbers that required repair or replacement as a consequence of timber decay, resulting from water ingress / damp penetration, but more importantly would also determine any timbers that were considered at risk, so as to allow preventative works to be undertaken, along with any targeted timber treatments.
The underside of Platform 1 at Basingstoke Station.
The surveys included conventional techniques along with full moisture assessment of structural and other timbers and also included the use of the Micro Probe used for the non destructive investigation of concealed timbers. (For more information on the Micro Probe and to see it in action click here)
Moisture assessment of one of the main supporting timbers.
On completion of the surveys (which were carried out over a three month period) detailed reports were provided outlining the extent and areas of required repair and any other maintenance issues required to prolong the life of the canopies.
The underside of platforms 2 & 3 Salisbury Station.
Typical Condensation beads of water and steamed up window glazing.
Surface mould growth on walls and ceiling
Condensation (beads of water) forming under window.
The advice given below can go someway forward to helping with the control of condensation and mould problems.
The Control of Condensation
The control of condensation is based on two very simple primary measures, supported by a number of secondary measures.
Primary Measures
1. Improve Ventilation.
Condensation mould generally occurs in areas where the walls are obstructed by furniture and other stored effects.
By improving general ventilation this will sweep away the internal moisture-laden air and replace it with drier air from the outside (yes, the external air is drier than internal air most of the year!)
Use mechanical extractors and ventilation (where fitted) and keep bathroom and kitchen doors closed during use to prevent moisture movement to other parts of the house.
2. Improved Heating.
Coupled with ventilation, heating should be set or applied to give a low-level background heat. This will ensure no rapid changes to the environment, and will facilitate slight warming of wall surfaces over a period of time, thus reducing the risk of condensation.
Secondary Measures
- Remove excess sources of moisture – avoid drying clothes inside the house and the use of liquid gas and paraffin heaters.
- Insulate cold surfaces.
- Prevent other sources of water ingress and penetration.
- Install dehumidifiers, these can remove excess moisture from the air.
- In areas of continued risk to mould, wash down walls with mould / fungicidal washes and redecorate using specialist Anti-mould paints.
Further condensation advice on the control of condensation can be found in our condensation advice leaflet. Click here to download our condensation advice leaflet.
Please note that the advice given above is given in good faith and does not constitute a specification for the control of condensation, if further advice or a survey is required please contact our office.
Premier Heritage has recently completed a timber condition and defect survey of historic Worsley Court House in Salford, Manchester close to the Bridgwater Canal.
Worsley Court House was constructed on the site of the old village stocks and completed in early 1849, soon after on the 4th August the first court hearing was held where two local men were accused of fishing on the Bridgwater Canal and on the private fishing ponds of the Earl of Ellesmere. They were apparently found in the possession of a large eel and a 6lb carp, with one of the men found guilty and allegedly fined two pounds, a lot of money in those days!
Although operating as a Court until 1908, the building has been used in many ways over the years and has served as the Town Hall, as well as being used for public functions, dances and concerts, in some way fulfilling the function of the village hall. In 1973 it was purchased by the Salford District Council and is now a distinguished venue for weddings, public meetings and other private functions.
Despite its traditional external black and white timber framing and decorative gabled walls the Court House is a purely Victorian building with lavish internally panelled walls and a huge fireplace.
The building, which is now Grade II Listed, has been extensively extended over the years with numerous wings being added, however like many buildings of its age and construction it is vulnerable to the affects weathering and dampness and over the past decade or so; various structural timbers have had to be replaced due to fungal decay.
Premier have undertaken a detailed survey of the timber framing, which included the use of the Micro Drilling system and well as conventional survey techniques to advise on the on incidence to timber decay and future repair strategies.
Front entrance to the Worsley Court House
Non destructive detection of timber decay
More conventional decay detection of a corner post
The timber panelled wall of the Oak room
Closer inspection reveals wet rot decay to decorative timbers
Paul Carter of Premier Heritage was delighted to be informed that he had won the recent photographic competition held by the Property Care Association (PCA). The PCA, which incorporates the British Wood Preserving and Damp-proofing Association (BWPDA), had held a competition to find some of the most interesting photos from within the property care industry. The winning photograph taken by Paul, was one of two entered and shows what is commonly referred to as plaster fungus, it is however a specie of non wood rotting fungi called ‘Ink Cap Fungus’ (Coprinus spp), a fungi that develops on wet brickwork, plaster or timber.
‘Ink Cap’ fungus growing on the underside of a timber lintel
The winning photograph shows the fungi development on a large timber oak lintel. Our other entry, Peziza spp, was taken in a fire damaged farmhouse that had been saturated as a consequence of extinguishing the fire and its continued exposure to the weather.
Peziza; plaster fungus development on saturated ceiling plaster
These pictures along with other entries can be seen in the current publication of the industry magazine ‘Property Care’.
Micro Drilling for the Structural Assessment of Timber.
What is Micro Drilling?
Micro drilling is a non-destructive timber investigation technique allowing the structural assessment of timbers and areas that can be hidden or obstructed by decorative finishes or plasterwork and can allow for cost effective care and repair of buildings without the loss of building fabric, which is extremely important when dealing with period or buildings of historic interest.
The Micro Drill cuts a fine 1mm probe into the timber to be investigated and through measuring the speed of penetration, records variations and defects in the timber caused by insect attack, fungal decay or other defects to a computer or field printer, allowing accurate assessment of the timber without the need for full destructive opening up.
The video below shows Paul Carter putting the Micro Drill through its paces….
This system of non-destructive timber investigation is of benefit when trying to assess the condition of built in timbers such as truss ends, bearer beams and lintels etc. and can also be used for large dimension joinery timbers. The system can be of great value to Architects, Engineers and Surveyors when proposing conversion, refurbishment and repair schemes of period and historic buildings as it allows minimal interference and the ability to provide conservation approaches to the repair strategy.
To arrange a timber survey through Premier Heritage click here or call 0800 0 199 211
A recent inspection of a 1930’s mid terraced house in Wiltshire exposed a farcical series of events due to the incompetence of the Chartered Surveyor undertaking the Home Buyers Survey and also the damp proofing specialist who (on the recommendation of the Surveyor) followed him.
This traditional cavity brick built, mid-terraced house was subjected to a Home Buyers Survey, which identified dampness within the front living room and rear dining room walls, as a consequence of which recommendations where made to instruct a Specialist Damp Proofing Co to undertake a full survey (standard recommendation) and carry out any remedial works.
After an investigation by a local damp proofing company, rising damp was identified and recommendations put forward for a chemical injection damp proof course and re-plastering to the value of £1800 + Vat.
No visual evidence of dampness to the front bay window
Apparently happy with this quote, the prospective purchaser’s builder expressed his concerns with the diagnosis, as the property had (what appeared to be) a perfectly good slate damp proof course (as was installed at the time of construction) visible to both the front bay and rear dining room external facing walls.
A second opinion was sought and Premier Heritage were invited to undertake a survey of the property for Structural Dampness which found the following;-
- No obvious external defects or sources of moisture
- No apparent internal decorative spoiling (other than badly applied wall paper)
- No obvious plaster deterioration
- No surface mould growth
- No significant levels of moisture within the skirtings or adjacent timbers
- However, high and consistent damp readings to ceiling height on both walls.
Question………What type of dampness would cause this?
Answer………. The Metal foil backed paper type of dampness.
Lifting the wall paper expose’s the metal foil paper responsible for the damp readings!
Wrong Diagnosis
The damp problem had been incorrectly diagnosed, as it was metal foil paper (under the wallpaper) that was interfering with the damp meter, causing it to give the readings. The user should however (if he had known what he was doing) been ‘put on notice’ to the fact that the readings were consistent throughout the walls height (unusual) and that there was no obvious spoiling of decorations / plasterwork etc.
This should have at the very least, made him suspicious and he should have looked beyond the damp meter readings. More importantly is the fact that the property had a fully effective physical damp proof course.
The Outcome
The survey and investigation of dampness in an occupied house can sometimes be restricted as destructive investigation cannot always be carried out or approved. The misdiagnosis of dampness in buildings generally results from the misuse of the ‘moisture meter’ as in this case, but one should not rely on the moisture meter alone and should depend on the surveyors experience, eyes and common sense, all of which will tell him far more than the moisture meter alone. But such instruments are there to support and aid in the diagnosis of dampness (if used correctly) and as such their importance should not be overlooked.
We were somewhat surprised that the Chartered Surveyor had failed to identify the problem and far too quickly ‘passed the buck’ to the damp proofing company. We were however not too surprised with the damp-proofing surveyors findings as he was not only inexperienced, but also held no formal qualifications in damp surveying.
The foil backed paper had been applied to the walls due to the colonisation of mould during the winter months, the mould clearly a symptom of a seasonal condensation.
The foil paper, marketed as an aid to ‘damp control’, was naively applied by the Vendor in an innocent attempt to eradicate the mould, which clearly was never going to happen.
Premier Heritage identified that no structural dampness existed within this property and therefore no works were needed. Following the removal of the foil backed paper and redecoration they all lived happily ever after, apart from the surveyor and the damp-company who were asked to contribute towards Premier Heritages costs, which could have been avoided had they looked beyond the end of their noses!
The station, which opened in August 1864, was the Isle of Wight railway’s northern terminus, (one of three stations in Ryde), before being expanded in 1866 to accommodate the opening of the new Ventnor to Shanklin line.
Ryde St John Signal Box
The timber framed, two storey signal box originally located at London Waterloo East, was dismantled in 1926, timbers numbered and moved piece by piece to be re-erected at its present location. This is the only operational signal box on the Isle of Wight line today and hence it has become known as the ‘Island Line Signalling Centre’!
No fancy computerised systems here! All hand operated by an experienced Signalman
Premier’s brief was to undertake a detailed investigation of the main structural supporting timbers and to prepare a specification of repair and preservation to allow for the continued use of the Signal Box well into the 21st century.
The main soft wood timber frame which sits on a concrete ringed foundation suffers from wet rot fungal decay and general deterioration, in part due to general weathering and the lack of routine maintenance, but also as a consequence of past flooding that affected the track and station buildings in the early and late 1990’s. Investigation of the timbers included the use of conventional survey techniques and moisture measurement, but also Micro Drilling using the Sibtec Digital Probe to determine the integral condition of the main wall plates, cill beams and large corner posts.
Significant wet rot fungal decay affecting the large corner posts and cill beams
Wet rot decay affects the internal wall plates
Wet rot fungal decay affects the joists to the canter levered jetty on the southern elevation
When the owners of a farm house suffering with damp problems needed a damp proofing solution Premier Heritage were on hand to assist with a traditional solution to damp.
This detached, stone built former Devon Farmhouse was refurbished by its previous owners in the 1970’s and unfortunately like many properties of this age was stripped of much of its original fabric, including its lime plasterwork, renders and pointing mortar.
Farmhouse prior to traditional form of damp proofing taking place
In early 2008 Premier Heritage received instructions from its new owners to undertake a full survey of the property for dampness and associated defects and to put forward a specification for remedial works to deal with the dampness present and any associated defects.
Drying out the dampness in the property
The main areas of concern identified by our investigation confirmed the presence of rising and penetrating dampness affecting various walls, although the latter mainly affecting the weather prevailing elevations and most noticeably the front sitting room, rear drawing room and stair area. No structural dampness was identified at first floor level.
As a consequence of the longstanding dampness to the lower sections of the south and western walls, several timber lintels were also showing signs of decay (some having already been replaced) and also death watch beetle activity.
Lintels showing signs of death watch beetle activity and fungal decay
The structural timbers supporting the half landing were also affected by wet rot where bearing into the wall as were numerous skirting and window boards.
To the western wall there was also the added complication of raised external ground levels sloping towards the house and also an obvious, insufficient overhang of the thatched roofing, increasing moisture at ground level and within the walls.
Replaced timbers
It was established that the conditions affecting this property had resulted as a consequence of the building’s past refurbishment and the removal of the original permeable mortars and renders used in the buildings original construction (i.e. the lime plaster, bedding and pointing mortar etc). Subsequent replacement with modern cement, being less permeable has resulted in dampness becoming trapped within the fabric of the wall ‘due to its inability to breathe’. This problem has built up over many years being further compounded by the numerous layers of masonry paint applied to the walls over the past 30 years or so!
Premier Heritage’s specification for remedial works concentrated on the removal of the cement materials (both inside and out) to allow the walls to dry down, along with subsequent repairs to structural and joinery timbers. The main contractor was appointed and the works were project managed by Premier Heritage.
The first task was to remove the external paintwork and cement pointing which was impermeable and trapping moisture / dampness within the wall’s, increasing the levels of dampness and internal damage to the building’s fabric. Having removed all external coatings and cement mortar (including that to the interior of the sitting room) the walls started to dry down.
New oak lintels were introduced, where existing were structurally unsound and timber repairs were completed to the interior staircase and landing etc.
Ground levels to the western wall were also reduced, with improved drainage and a vertical slate barrier fitted to the lower sections of the wall to minimise damp penetration.
Following the drying period re-pointing commenced to the exposed stone walls and this was undertaken using a lime based (permeable / breathable) mortar, after which the building was re-thatched and finally redecorated throughout.
The building has now been restored to its former condition and is dry and comfortable as well as looking great!
The finished farmhouse free of damp
