The screw that’s improving timber frame builds

When Craig Smith joined ITW Construction Products (ITWCP) as a research and development graduate, he didn’t expect to be leading product development within two years. But by October 2023, he’d stepped into the role of Product Manager for the Cullen team. Less than a year later, his innovative thinking and hands-on approach earned him the Innovation Champion of the Year award at the TRA Roofscape Design Awards.

Craig’s standout achievement? The development of the Cullen Head Restraint Screw (HRS) system, which addresses long-standing issues around partition walls, deflection, and noisy floors and offers a simpler, smarter way to meet NHBC guidance.

Starting with a problem

The challenge was clear – housebuilders and timber engineers needed a reliable way to restrain internal partitions while still allowing vertical deflection between floors.

Many of the existing solutions were complex, inconsistent, or failed to fully meet NHBC technical requirements (sections 6.3.9.3 and 6.4.9). This could lead to cracks in plasterboard, squeaky floors, and even failed inspections.

Craig took this problem seriously. He collaborated with customers and technical stakeholders to understand where current solutions were falling short and how the Cullen product range could fill the gap.

“Rather than reinvent the wheel, we focused on designing a product that would make life easier on-site and solve multiple issues at once,” Craig said. “It had to be simple to use, reduce callbacks, and work reliably across a range of projects.”

What makes the HRS system different?

The HRS system combines a specially engineered screw and a recyclable guide that connects to joists or trusses while allowing for a 14mm deflection gap. This gap is crucial to accommodate vertical movement in the building without putting pressure on partition walls.

The system provides:

• NHBC-compliant lateral restraint for internal partitions
• A quieter floor by reducing movement-related squeaks
• Reduced risk of plasterboard cracking and fixing defects
• The option to pre-install plasterboard, saving time on site
• A single screw type with no pre-drilling required
• A 100% recyclable guide that ensures consistent installation

It’s a small component that delivers big improvements in build quality, installation speed, and sustainability.

From university project work to real-world impact

Craig’s route into construction innovation began at Strathclyde University, where he studied Product Design and Innovation. While studying, he worked part-time as a kitchen designer at B&Q, where he gained valuable experience in understanding customer needs and how people interact with products.

He joined ITWCP in 2021, working in the test lab at Glenrothes. There, he supported product development and testing, learning how to turn creative ideas into practical, safe, and standards-compliant solutions. This experience laid the foundation for his future as a product manager.

“Craig has a real talent for combining creativity with technical detail,” said Sam Kirkham, who nominated him for the award. “He listens, tests, and refines until he’s confident the product will work just as well on-site as it does on paper.”

Making innovation practical

The Cullen HRS system is now available to customers, supported by a short features-and-benefits video that helps explain how it works and why it matters. Builders using the product have already reported fewer issues on-site and improved confidence in their NHBC inspections.

Craig’s success is a reminder that innovation in construction isn’t just about high-tech solutions or dramatic redesigns. Sometimes, it’s about improving the things we take for granted and doing it in a way that benefits everyone from the factory floor to the final handover.

As the TRA Roofscape Design Awards continue to shine a light on the industry’s rising stars, Craig’s work is proof that the next generation of designers and engineers is more than ready to lead.