The AFI, which represents manufacturers, stockists, installers and contractors dealing in various types of fencing (including timber and metal fencing), issued a statement after conducting a survey across the industry attracting 200 responses.

The AFI said over 75% of respondents had experienced treated timber post failures between 2006 and 2012 with the figure rising to 90% for failures since 2012.

It has been lobbying for a guarantee scheme whereby timber suppliers accept responsibility and costs for such failures, including the replacement work.

Just supplying replacement posts, it says, is often only 20% or less of the cost to repair or replace the fence.

AFI said products need to consistently guarantee a service life of 15 years as set out in BS8417:2011, Preservation of Wood – Code of Practice covering desired service life of treated timber.

“In the light of this evidence the Association of Fencing Industries has no choice but to recommend to all installers that they only use chemically treated timber in ground contact where this is a specific requirement by the client and that the client is made aware that failure of the posts due to fungal attack is not the responsibility of the installer,” AFI chairman Cameron Glanvill said in a statement.

The Wood Protection Association (WPA) told TTJ it was open to resuming dialogue with AFI but pointed out that a supplier “guarantee” scheme covering remedial work costs was very difficult to operate in practice.

“The efficacy of industrial wood preservatives has been independently verified by the UK Health & Safety Executive as required by current biocidal products regulations,” said Gordon Ewbank, WPA CEO.

“Confidence is further underpinned by early results from the large-scale UK field trial, managed by BRE, plus of course the manufacturers’ supporting test and field data.

“The WPA believes that the three-fold keys to ensuring the long-term performance of treated wood products is to ensure a) accurate specification, b) the use of treatment companies with third-party accreditation and c) being prepared to pay for quality.”

WPA has embarked on a major supply chain education programme, based on these themes, in collaboration with the Timber Trade Federation, Confor and the Timber Decking and Cladding Association. “We would be delighted to invite AFI to be a part of this important initiative,” said Mr Ewbank.