By Jim Coulson, Director of TFT Woodexperts Limited
I recently wrote about Scaffold Boards; and I highlighted the fact that a good many of those that are in use every day in the UK are not “BS” boards – that is, they have never been graded to BS 2482 and have never been independently verified. In this article, I want to expand on the theme of wood-based construction products that are essentially not what they claim to be; and show you how a simple “add-on” instruction to the specification or order can solve that problem.
As I have said above, there is a British Standard on Scaffold Boards, but relatively few people in the industry seem to know of its existence. Or if they do know about it, more often than not they ignore it completely and use what are really no more than ungraded “planks of wood” for their scaffolding. But many of those planks are inherently unsafe, since nobody has ever established their correct grade or rejected the potentially dangerous ones from the consignment.
The Importance of Grading and Independent Inspection
Every piece of timber – used in whatever way – has the potential to contain natural defects, which may have a greater or lesser effect on the performance of the piece. Sometimes those defects will only affect the timber’s decorative or cosmetic appearance – a fact that is important in furniture or joinery products, for example. But sometimes those defects will affect the timber’s load-bearing abilities – which is of much more vital importance in structural timbers (such as beams & joists) and of course, in scaffold boards too.
But it is unfortunately the case that the more serious structural defects are far less obvious to the untrained eye: and yet they can be far more serious in their consequences than are the “cosmetic” defects that most people see first of all, when looking at a piece of wood. It is almost impossible to tell, without proper training, whether any piece of wood is structurally “safe”. Many workers will reject timbers that contain splits: based only on a “gut instinct” which tells them (wrongly!) that the board must have been weakened in some way. And yet the majority of such “split” boards will still have more than enough strength to do the job: and they need not be rejected – even though that seems to be counter-intuitive. Conversely – I could even say perversely – workers will use boards which contain large knots or which have serious grain deviations in them, which they ignore (or more probably, they don’t actually see those “natural” features of wood as being a problem). Yet such timbers will be much less able to carry a full load when put onto a scaffolding or into a permanent structure.
But it’s not just structural timber products that need grading and checking. For example, tiling battens need to be graded to BS 5534 before being permitted on all NHBC sites: and yet many of the tens of thousands of such battens out there will not have been graded or independently checked before use. The same goes for plywood; which is now supposed to be CE-marked before being used in any permanent use in building. But you will know as well as I, that there is still a lot of very poor quality plywood out there in the market place; even though, theoretically, it should all be “reliable”. So how can you be sure that you get what you need? The answer is to ask for products to be third-party Certified.
The TFT Diamond Mark (audited by our sister company, Technology For Timber Limited) is not just a stamp mark on wood products – though of course that’s what it looks like – it is actually an assurance that the product has been correctly made and, more importantly, fully checked for compliance with the relevant Standards, to make sure that what is asked for is what is actually received by the customer – and that it does its job properly, consistently and reliably!