Use of sheathing boards as part of a through-wall construction with timber or steel frame systems (SFS) is not a new concept. Most will be confident in the competent installation of sheathing boards in these applications, but given the wide range available across the market, John Taylor, technical director at Euroform Products, explains why the installation method for this external finish needs careful attention.
Regardless of which external wall finish is used, there is an ever more demanding requirement for sheathing materials to be not only quicker to install, but also capable of contributing towards securing other elements within the facade system.
The challenge where a brick facade is concerned is that not all sheathing boards have pull-out capability while remaining workable. Those that do provide adequate pull-out performance are able to act as a potential contributor to securing back
any thermal insulation.
Importantly, sheathing materials better suited to SFS are medium density to help install speed. It is this density which enables the product to be ‘scored and snapped’ as opposed to using sawing equipment on-site.
While these types of sheathing boards provide practical on-site benefits, when using with SFS, particular attention must be paid to the expansion gaps required and the fixing types used.
It sounds like common sense, but few realise that fixing types specified are not just ‘recommended’; the sheathing board will have been systematically tested for factors, e.g. loading and fire performance, using the specified fixing type. Any deviation from fixing type or profile of fixing methodology means the installation does not comply with the specification tested – and performance cannot be guaranteed.
Unlike facades, where the carrier rail and SFS will generally take the load of the cladding tiles or panels, with brick, the sheathing board plays a more integral role in the performance of the overall wall build-up.
It is therefore essential that installation guidelines are followed – with attention to fixing type, profile, expansion between board joints and edge fixing distances.
The trend of using SFS with brick is not expected to decline anytime soon, which makes it a real opportunity for contractors. So, if you’re bricking it… make sure you’re fixing it right.