Home Treatment Guidance Guidance on how to: TREAT FURNITURE TO CONTROL WOODWORM
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Guidance on how to:

TREAT FURNITURE TO CONTROL WOODWORM

to-treat-furnitureEffective treatment of wood against wood boring beetle infestation requires all surfaces to be coated with the correct amount of woodworm treatment fluid. Invariably furniture has many painted and varnished surfaces thus access is restricted resulting in less effective treatment. In addition the treatment of man made materials such as ply is severely restricted by the presence of glues. Woodworm treatment fluid is suitable for treating the bare exposed timber surfaces of furniture and this normally requires two generous brush applications to achieve the desired coverage rate.

 

Notes on the treatment of furniture:

  1. Make certain the infestation observed is active. If necessary monitor suspect areas by filling exposed flight holes with wax polish then checking to see if any new holes appear over a twelve month period.
  1. Do not apply treatment to painted, varnished or polished wood surfaces - It will have no effect. If treatment is essential the decorative surface will have to be removed to expose the bare surface of the wood for treatment to be applied.
  1. Be careful not to confuse fine wood dust generated by pulling out and pushing in timber drawers on timber runners with frass (bore dust) caused by wood boring insects.
  1. The life cycle of the Common Furniture Beetle is three to four years. It is possible therefore that you may see some new holes and piles of frass even after you have treated as different generations emerge through the treated surface. This may cause alarm and it could happen for up to four years after treatment but thereafter no new holes should appear. Remember it is as the insect emerges and comes into contact with the treated surface the contact killing properties of the woodworm treatment works. As a precaution after four years you may wish to apply one further coat of Woodworm Treatment to protect any new timber surface exposed by any new flight holes. (See 'How does woodworm treatment work' above for further guidance)

Heat treatment of furniture and artefacts - when fluid application is not possible

Certain artefacts and valuable pieces of furniture are not suitable for conventional fluid treatment so an alternative method is to employ a carefully controlled heat treatment process. It is not just a matter of putting things into a large oven and heating them up as this would cause rapid drying resulting in twisted and distorted wood. A technique developed in Germany by Thermo Lignum, uses a purpose-built chamber equipped with very sensitive and responsive temperature and humidification control. The principle is to ensure stability of moisture in objects during the cycle of elevation to the desired temperature and the return to ambient temperature.

 

The table below illustrates data generated by exposing test wood boring insects to the Thermo Lignum heat treatment process and the temperatures that have to be reached in order to achieve a 100% kill of all stages of: Common Furniture Beetle (Anobium punctatum), Powder Post Beetle (Lyctus brunneus), Death Watch Beetle (Xestobium rufovillosum) and House Longhorn Beetle (Hylotrupes bajulus)

 

Species

Temperature °C producing

100% kill of test insects

Common Furniture Beetle

50

Powder Post Beetle

50

Death Watch Beetle

47

House Longhorn Beetle

55

[Data summarised from Ertelt* 1994]

 

The actual period of exposure to the peak temperature needed to kill all stages of the insects is probably much less than an hour but in order to achieve the stability of temperature and humidity in the object during the heating and cooling period the actual treatment in the chamber from start to finish will normally take between 15 and 24 hours.

 

*Ertelt, P [1994], Studies on controlled thermal treatment in pest infested wood. Diploma Thesis, Rosenheim Technical College, Germany, [In German, English translation via Thermo Lignum UK]

 

Peter Macdonald 2009

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