I read with interest Charles Trevor’s guest column in this week’s TTJ and it prompted me to write about the way in which our trade “wastes” much high value wood in construction, by perpetuating ridiculous prejudices about appearance, when specifiying and using structural graded timber.

By this, I mean the ever-increasing prevalence of purchasing specifications insisting on “limited” blue stain in C16 and no blue stain at all in C24. Does the timber trade not know that blue stain is allowed in unlimited amounts in correctly-graded structural wood – even under the new European Rules controlled by EN 14081?

I deal with exporting mills a lot – and I train graders to produce C16 and C24 for the UK and I also train them in C18 and C30 for their European customers – and the most frequent complaints I get are concerned with UK buyers placing limits on blue stain: even when the newly-trained graders have been told that the rules (which indeed they do) permit 100% blue stain in all grades.

Of course, I understand that nobody would want to receive a pack of 100% entirely stained wood; but a reasonable percentage of pieces in any pack with some degree of staining – even, dare I say, in C24 – should be no problem.

Essentially, this prejudice comes from a complete misunderstanding of the end use of structural softwood; where it is being regarded as though it is “appearance graded” wood from the days before strength grading was introduced – and that was over 40 years ago!

Yet the clue is in the title: “strength” – when that is really all that matters. After all, how much structural wood do we actually see in any finished structure? None! It’s all hidden – behind the walls and wallpaper, under the floors and the carpets, and above the ceilings. So why on earth should it matter if it looks a bit discoloured, so long as the grain is adequately straight and the knots aren’t too big?

For all of our apparent lip service paid to “green” targets and the careful husbanding of scarce resources, this is the real scandal of wasted, high quality timber, which has dogged our trade for the past 30-plus years – and it’s getting worse, not better. We as an industry need to educate our customers to accept ALL timber that is fit for purpose, and not to restrict what we are prepared to accept, to the unscientific concepts of a beauty parade!

Jim Coulson
Director
Technology For Timber Ltd