Resources
May 2011 Timber Treatment
Welcome to May's email bulletin. This month our topic is timber treatment. If you have a subject that you would like us to cover in a future bulletin let us know by emailing the team at info@spabfim.org.uk.
Things to think about...
Throughout history, timber has been used as a structural material in walls, floors and roofs and can last indefinitely if properly maintained.
Any problems are usually attributable to dampness and a lack of ventilation, which can lead to fungal infestation and wood-boring insect damage.
Generally speaking, wood-destroying fungi fall into two categories, commonly known as wet and dry rot. Dry rot (Serpula lacrymans) is the most aggressive wood-destroying fungus and thrives in unventilated voids. It often has a musty smell and can develop into grey or white cotton wool-like sheets with tiny orange spots. Wet rot is a generic term that refers to decay occurring in very damp conditions. An example is the cellar rot fungus (Coniophora puteana), which may be identified by dark brown strands appearing on the surface of the timber. This fungus commonly causes exposed wood to soften and lose strength.
Where there is rot we may also expect to find wood boring insects such as furniture beetle (woodworm) and the larger deathwatch beetle at work, as they are attracted to warm, damp, unventilated conditions. Flight holes and bore dust are typical symptoms.
It should be remembered that these fungi and insects all have one thing in common: they generally only cause significant damage where dampness exists. If rot or insects are present, this often indicates an underlying fabric problem. As dry timber is less vulnerable to attack, successfully arresting decay involves eliminating moisture and promoting drying.
It is always preferable to
tackle rot and insect attack by improving the environmental conditions rather
than resorting to chemical treatments.
It is also worth remembering that oak, chestnut and certain other hardwoods are generally very durable and grow harder with age. This means that they have a natural resistance to decay and insect attack. On the other hand, softwoods such as pine and fir, are generally less durable and need to be painted to protect them from decay.
Things to do...
If areas of softwood have previously been painted, make sure that the integrity of the surface is maintained. This will probably mean repainting external timberwork every few years. If the surface is allowed to break down, water can penetrate the cracks and become trapped leading to decay.
If you suspect that there is timber decay
or possible insect infestation in your building, seek advice from your
professional advisor, rather than someone with a vested interest in a method of
treatment. Wholesale timber treatment
with chemical preparations is rarely necessary but independent advice from a
timber specialist (rather than a treatment company) may occasionally be
required.
Also, remember to ask your cleaning team if they have swept up any insect debris. Evidence of insect attack is often cleaned away and not reported!
Further information
- Brian Ridout, John Fidler and Ingval Maxwell (1999) Timber in Buildings: Decay, Treatment and Conservation: The Conservation Approach to Treatment. Spon Press.
- Richard Oxley (1999) SPAB Information Sheet 14: Is Timber Treatment Always Necessary? SPAB.
- Timber Decay by Dr Jagjit Singh - an article available on the Building Conservation Directory website.
- Insect Damage to Timber by Brian Ridout - an article available on the Building Conservation Directory website.
SPAB launches online membership application
The SPAB is a registered charity and our work in training, technical advice and casework is dependent on the support of members and others willing to help financially. We receive some contributions from publicly funded bodies such as English Heritage and Cadw and we have HLF support for the Faith in Maintenance project. Most of our funding, however, currently comes from membership fees and from donations and bequests. If you are interested in joining the SPAB you can now apply to become a member via our website. Members receive our quarterly Cornerstone magazine (which includes information about lectures, visits and courses) and also have access to our Properties List and Regional Group Events via the members' pages on our website.
National
Churches Trust Survey ~ report published
The importance of church buildings to communities has been revealed in the results of the report of the National Churches Trust Survey, which has recently been published.
Undertaken in 2010, the survey was the largest exercise of its kind. Open to all of the estimated 47,000 churches, chapels and meeting houses in the UK, the survey was unique in seeking to understand not just the physical condition of places of worship but also the way they are managed, funded and used by their communities.
Find out about National Churches Trust Survey.
Need more help?
If you have any questions about maintenance or repair issues contact our Technical Helpline for advice and guidance. This service is normally available on Fridays between 9.30am and 3.30pm on 0207 456 0916. Alternatively, you can email your questions to advice@spabfim.org.uk. Copies of the SPAB's range of Technical Pamphlets and Information Sheets are available to purchase from our online bookshop.
Sara Crofts
Faith in Maintenance Project Director
Stave off decay by daily care ~ William Morris 1877
