The secret? It’s built with cross-laminated timber (CLT) and assembled by robust Bosch tools. Not much of a secret maybe, but in terms of making it work G-Frame structures has it cracked. The company has also recently been on site installing the CLT superstructures for two multi-storey Passivhaus apartment buildings located on a small island between two canals at Blaker Road in Bow, east London. The project comprises seven residential Passivhaus units in total, along with the refurbishment of the lock keeper’s house. Because of complicated site access all the tools and equipment had to be lifted in by crane.
Project Manager, Jamie Vowles, leads his crew of seven – that’s all he needs to complete the job from start to finish. “I love it and my team loves working with CLT,” he explains. “There’s no dust, no vibration and you’re working undercover once the first level is installed, which is usually by the second week.” From a management perspective, CLT construction works too. Only one small skip is needed to handle waste and there are fewer deliveries to disturb the neighbours. The footprint is considerably smaller too which means less disruption to the locale, an important factor in planning terms. With energy savings at the top of many agendas, the carbon-neutral and, in some cases, carbon-negative nature of CLT makes it – on paper – a perfect choice. Jamie mentions: “I don’t understand why more contractors aren’t opting for CLT. I’ve worked with it for nine years and it is the best system as far as I’m concerned.”
G-Frame’s design team model the CLT panels through the BIM platform and send details directly to the manufacturer’s CNC machine where they are cut to size with any apertures and service channels included. This direct link ensures accuracy and speed when transferring data from the structural design and greatly reduces procurement time. Michael Smith is part of Jamie’s crew and has been building all his life: “Working with CLT suits me, I’d rather work on a project like this than with bricks and blocks; it’s a cleaner and more pleasant workplace. The key to working with CLT is torque. Bosch is the only tool that supplies the torque we need without breaking its collar.”
Finding the drivers and combis to deal with screws that can be anything up to 300mm in length, that need to drive through the cross laminates, especially when up against 200mm of solid timber, was not easy and Jamie ran tests to see which range could deliver on both the torque and gearing.
“Bosch was the only tool that didn’t break – its metal collar gives it the strength we need and I think, being developed in Germany, it’s robust and built for the job. We’ve got eight 18 volt drills working at any one time; they’re all cordless, so quieter; which is good for our neighbours – and we’re drilling 50 panels a day.
“There aren’t many drills that will do that. We’ve a mix of cordless GSR drill-drivers, cordless GDR impact drivers and cordless GDS impact wrenches. The batteries are good too, we have a bank on charge and each charge delivers around 40 screws. It’s a great partnership.”
There have been many false dawns when it comes to timber construction, but as the advantages and pressure to create new housing ramp up, and the tools exist to make it easy, perhaps it’s time to move it mainstream.