Norbord’s £95m investment in its new plant in Inverness is well documented and the company has already celebrated the line’s first year of operation with a visit by the Duke of York.

The investment in the new continuous press line has enabled the company to bring new products to market and these include the SterlingOSB Zero range of zero-added formaldehyde (ZAF) boards, which Norbord says are aimed at “safer construction and healthier buildings”. Formaldehyde is a known carcinogen that can pose a health risk, especially when the board is being sawn, drilled or sanded.

Unlike traditional OSB containing ureaformaldehyde (UF) or melamine-ureaformaldehyde (MUF) binders, the new SterlingOSB Zero family uses a methylene diphenyl diisocyanate (polyurethane MDI) resin to bind the thousands of strands that make up each board.

As well as being healthier, a ZAF board offers superior performance compared to conventional low-emission boards made with UF or MUF, said Norbord.

“The MDI binder has better mechanical properties including a stronger internal bond and a lower modulus of rupture than UF/MUF boards,” said a spokesperson. “A ZAF board is more moisture resistant (subject to less swelling in humid environments such as kitchens and bathrooms) and is stiffer and less prone to ‘creep’. The pMDI resin in a ZAF board is suitable for hot and humid climates, unlike boards containing UF or MUF resins. Boards made with pMDI binders also contain less resin – and hence more wood – than traditional boards, meaning they are ‘greener’,” he added.

SterlingOSB Zero is also more environmentally-friendly to produce, said Norbord. The pMDI binder cures at a lower temperature than UF/MUF resins so less heat energy is consumed during manufacture. It is also safer to produce since pMDI resin uses water as a catalyst in the curing process; UF/ MUF resins need the addition of ammonium nitrate – an explosive chemical – to harden.

The range comprises SterlingOSB Zero 3 structural board; SterlingOSB Zero Tongue and Groove, a precision-engineered T&G board for use in flat roof decking and flooring applications; SterlingOSB Zero SiteCoat for site hoardings; SterlingOSB Zero Fire Solutions, developed in response to the Structural Timber Association’s guidelines for reducing fire spread; and SterlingOSB Zero StrongFix, which is designed for dry lining applications.

Acoustic flooring

While Norbord has made no secret of the fact that its UK investment focus will be on OSB production, it continues to develop new chipboard and MDF products.

One such is CaberAcoustic, an upgrade of the company’s CaberFloor P5 chipboard flooring product.

The new product comprises 18mm or 22mm CaberFloor P5 chipboard with a 10mm acoustic felt layer permanently bonded to the underside.

Designed as a floating floor laid over an existing deck in either new-build or refurbishment applications, CaberAcoustic is installed with the T&G joints glued with CaberFix D3 adhesive and all perimeters of the panel sealed with acoustic flanking strips.

When fitted to an existing floor in a conversion or refurbishment application, CaberAcoustic is overlaid onto the existing deck and a Hush Sound Absorber layer fitted between the joists with Hush Resilient Bars screw-fixed to the underside of the joists at 600mm centres. The addition of two layers of 15mm Soundbloc plasterboard to the underside of the resilient bar and all perimeters sealed with an acoustic sealant prior to skimming, ensures that the floor structure complies with UK Building Regulations Approved Document E for separating floor constructions in refurbishment and conversions.

In new-build applications, CaberAcoustic is laid in a similar manner (T&G joints glued and the perimeter sealed) over an 18mm or 22mm chipboard deck but a Hush-MF system should be applied to the underside of the joists to create a void of at least 150mm from the underside of the joists to the back of the plasterboard lining.

A double plasterboard layer comprising a 19mm plasterboard plank and 12.5mm Soundbloc completes the system. Both ceiling structures also provide one hour’s fire protection.