Action to address sub-standard truss rafter timber has been delayed following a reappraisal of the incidence of material failure.
More stringent machine settings were expected from the UK Timber Grading Committee (UKTGC)after tests of trussed rafter timber which uncovered ‘unacceptably high’ failure rates with some packs of imported material.
The testing – commissioned by UKTGC and the Trussed Rafter Association – was instigated in response to end user concern that TR26-graded truss timber was breaking up during production.
In a statement earlier this summer TTF product manager Nick Boulton said that UKTGC could ‘almost certainly’ issue new machine settings by the end of June for European redwood and whitewood graded in non-Scandinavian countries.
However, the new settings have not yet appeared and an immediate tightening of the regulations now looks unlikely. In a letter to members, UKTGC chairman Paul Marsh states that required amendments to settings would have a ‘devastating effect on pass rates for some producers and, in consequence, costs for the users’.
He adds that immediate action would be unreasonable on the basis of a small failed sample. The UKTGC is referring the issue to the building regulations authorities for guidance.
Mr Boulton said: ‘There is some cause for concern but not enough to warrant urgent action. The small sample of the tests could be distorting the results. If we expanded the research we could find there isn’t a problem.’
Mr Marsh added: ‘The tests were based on a very small sample – four packs – and the failures were not that bad in any case. The tests involve putting a far greater strain on the timber than would be put on a roof.’
