Copper treated battens – the hidden truth

Sep 29, 2015 Off Comments in General News by
Copper treated battens – the hidden truth

There are banks of information currently circulating within the industry regarding changes to BS 5534:2014 – and quite rightly too. One of the major updates refers to the increased number of fixings which now must be used to hold tiles securely in place; this has contributed to investigations and testing works carried out by S R Timber which have uncovered a few issues that have not been highlighted until now.

Roofing battens come in an array of different colours and shades; did you know those different colours can mask different types of preservative treatment? It is a common belief that green-coloured battens have been treated with a copper-based wood preservative – but how does this affect contractors?

(BS 5534 states that when treated, battens must be done to Use Class 2, according to the Treatment Standard BS 8417).

It is really important to know whether your batten contains copper or not, as copper can cause corrosion and premature failure of your fixings. The most recent edition of BS 5534 (dated 2014) now requires all slates and tiles to be fully fixed, using increased amounts of nails and/or clips, as appropriate. Although the usual make of fixings are either zinc-galvanised or aluminium nails/clips, in actual fact, both of these metals react adversely with copper in damp conditions. These ‘electrolytic reactions’ can, not only result in damage to the fixings, in addition, they can degrade the membrane as well.

So in order to meet BS 5534: 2014 requirements, are there any alternatives? Yes: either to use different types of fixings – stainless steel for example – or to simply buy battens that don’t contain copper. If your battens do contain copper, it’s a good idea to accompany them with water-resistant membranes, to avoid any dampness/damage.

Referring back to my original question, how can youtell whether your battens have copper in them? As I mentioned earlier, if they are green, there is a very high chance that a copper-based treatment has been used; this would give you an idea of the best kind of fixings and membranes to use.

However, if your battens are another colour, how can you tell if they contain copper? As obvious as it sounds, when you buy battens for a project, be sure to ask your supplier what they have been treated with. If you’re still unsure, ask for treatment certificates or data sheets. Taking these precautions will help avoid any complications arising some time after the project is completed.

Bearing all this in mind, did you know that S R Timber’s renowned Gold Batten is made with no copper treatment whatsoever? ‘Gold Batten’ is SR Timber’s highest grade of roofing batten, fully compliant to all standards and contains safe organic chemicals only that will cause no damage to the membrane or fixings. . They incorporate a unique and distinctive gold colouration which does not hide any potential defects that can be found within traditional battens.

The bottom line of buying battens is you need to be vigilant and sure of what you’re buying. It’s important for contractors to feel confident that the project they’ve completed is not tainted by unreliable materials. Aim to eradicate any ‘hidden problems’ at the earliest stage possible.