It goes without saying that timber is an incredible building material. As well as being renowned for its strength, durability, and high levels of insulation, it has low levels of embodied carbon. As a result, the government published the ‘Timber in Construction Roadmap’ to grow more trees and unlock the potential of this construction material.
Scotland is arguably at the pinnacle of timber frame housebuilding in the UK, with 92% of homes being built from the material.
In comparison, just 9% of new homes in England are built from timber. But that has to change, and it has to change fast.
Embodied carbon targets are increasingly common in construction and while there are no legal limits yet, they’re anticipated. Properties built using timber can contain up to 60% less embodied carbon than those built using traditional methods, so it makes sense that volume housebuilders are making the switch from bricks and mortar to timber.
Barratt, for example, has announced the construction of a new £45m timber frame factory, which it says will help it meet the government’s new energy efficiency, low waste-focused Future Homes Standard (FHS). Taylor Wimpey is investing in a fully automated new timber frame plant, and Persimmon has recently secured planning permission for a new facility for its Space4 timber frame division, which will be the largest of its kind in the UK.
This is reinforced by the report we commissioned from analysts AFRY, which showed the ‘addressable market’ in Europe for OSB, plywood and SIPs for timber frame construction will rise from 35 million m2 annually to 50 million m2 in 2025. The greatest potential is seen in the UK, with a current addressable market of 13 million m2.
So how can board manufacturers add to their portfolio to support this growing market? The key is to ensure their products can address the needs of housebuilders – and to do this they need to understand the issues they’re facing.
Housebuilders need to deliver homes in volume during a growing skills shortage – without compromising on quality. Changing legislation requires them to improve the performance of the homes they construct, delivering greater levels of thermal performance, energy efficiency and acoustic performance.
At the same time, legislators have also taken steps to close the ‘performance gap’ – the difference between how the property performs on paper and how it actually performs when it’s built. Approved Document Part L 2021 for example, now requires every new home to be tested for airtightness, rather than just a statistical sample.
This means specifiers are keen to use products that will help them close the performance gap. But there are many products and methods regularly used on site simply because ‘that’s how it’s always been done’ or because of a lack of awareness about the benefits offered by newer alternatives.
Take new-build home weatherproofing for example. In timber frame homes, this has traditionally been achieved using housewrap – a loose product that is fixed to the outer face of timber frame structures by hand.
Installation of housewrap can be both labour intensive and time consuming. Installers must ensure laps go in the right direction and undertake tricky installation details around window and door openings.
Incorrect detailing around doors and windows can reduce performance, and the product can also be torn. This can happen during installation or in windy conditions, plus housewrap can often be inadvertently damaged by other trades, and this minor damage can become a full-scale rip if it’s caught by the wind. As a result, airtightness is compromised, and moisture can penetrate behind the wrap and into the frame structure.
Today though, thanks to overlay technologies available for OSB or plywood sheathing, there’s an alternative to housewrap that means board manufacturers can offer considerable benefits to their housebuilder customers.
High performance overlays are a proven way to provide fast and effective weatherproofing in the US – and products such as the new Arctek Dryshell from Arclin, are now available to board manufacturers here in the UK.
Developers are always looking for ways to use their workforce more effectively and efficiently. Unlike traditional housewrap, high performance overlays are applied to boards used for timber frame walls and roofs, SIPs systems and cassettes in the factory. This means it’s already in place when the wood frame arrives on site, so once joints have been taped, skilled tradespeople can quickly move onto the next phase of construction.
Overlays also provide instant moistureand UV-resistance along with vapour permeability and improved airtightness. This not only extends the life of modern building components but will also give housebuilders confidence that the home will perform as it is designed to, because moisture cannot penetrate the building fabric and airtightness is maintained.
As well as protecting the building envelope from moisture ingress and condensation, overlay technology can also help to improve energy and thermal performance and the acoustics of modern buildings.
Essentially, performance overlays offer housebuilders a unique combination of benefits. They not only offer all-round enhanced performance but speed up the installation process and save the developers – board manufacturers’ customers – time, money and labour. All of which gives board manufacturers a competitive edge over the competition.
What’s more, manufacturers also have the reassurance that added-value products are less likely to fluctuate in price than the raw material, helping to provide the company with long-term stability.
There’s also little or no requirement for additional investment, as applying high performance overlays to OSB or plywood sheathing boards is usually a quick and simple process that can be integrated into the manufacturing process.
For housebuilders, the conflicting pressures of meeting stricter legislation while delivering quality homes at volume and speed are unlikely to ease anytime soon.
So, board manufacturers that can show innovation by offering products with high performance overlays will demonstrate they understand their customers’ needs – something that will help them capitalise on the growing timber frame market.
ARCLIN LAUNCHES ARCTEK DRYSHELL
Arctek Dryshell from US manufacturer Arclin is designed as an integrated weather barrier system for OSB or plywood sheathing boards for timber frame walls, SIP systems and cassettes (see pp23-26). It is thermally bonded to sheathing boards and provides a costeffective alternative to housewrap for timber framed homes.
Products made using boards with Arctek Dryshell are quicker to install and the weatherproof properties built using them are applied at the factory before they arrive on site, without the risk of performance being compromised by tearing like traditional housewrap. As a result, manufacturers can help their clients reduce costs by effectively removing an entire stage of the construction process, while increasing home performance and reducing risk.
Arctek technology is fully flexible and can be designed to meet project demands or market requirements. The level of customisation that can be achieved makes it ideal for high-value and specialised projects and enables special requests without delays.
It can usually be applied by board manufacturers using their existing machinery, so requires no investment in additional technology or outsourcing. Arclin will provide technical support regarding press schedules and materials testing to ensure board manufacturers can achieve the factory precision required.
To enhance your product portfolio with Arctek Dryshell order a sample at arctek. arclin.com/order-samples/ or to make an enquiry, visit arctek.arclin.com/make-anenquiry
