Sheffield AMRC testing gets ex-builder’s revolutionary aid to market

Ken Johnson’s start-up company KEAH created the Roof Batten Joint – a plastic injection-moulded, push-fit to connect horizontal wooden roof battens at any point along a roof structure.

The object was to make construction work safer but also to enable faster and easier assembly.

“After working in construction all my life and having first-hand experience of the issues that can cause delays and cost resources on site, I thought there must be a smarter way to complete those time-consuming intensive manual jobs,” said Johnson.

However, the company’s ability to interest buyers depended on being able to prove its greater load-bearing capacity.

Johnson turned to the AMRC, part of the University of Sheffield. The AMRC’s Advanced Structural Testing Centre.

The ASTC applied its bespoke testing technique that included strength testing 28 configurations of the batten joints using a Moog control system and the ASTC’s own ‘Tall Rig’ developed with Sheffield-based Gripple UK.

ASTC head Phil Spiers said: “We applied loads to the KEAH joints using the rig until failure of the roof batten, noted the mode of failure and the maximum load achieved just prior to failure.”

Results indicated that the KEAH joints were capable of carrying an average of 10 stone more than a traditional joint.

Testing is invaluable as it means we will now be able to approach our potential end users and confidently state the load bearing weights of our product

Ken Johnson, founder, Keah

Added Spiers: “Our tests have so far shown that the joints are stronger than traditional nailed roof batten fixtures and experience lower rates of failure. We have validated that the optimum load weight for use is 20 stone, but the joints can support all the way up to 50 stone in weight.”

Johnson, whose company received SME grant funding from the High Value Manufacturing Catapult for up to 50% of testing costs, said the help had been crucial.

“The testing is invaluable as it means we will now be able to approach our potential end users and confidently state the load bearing weights of our product and that the joints are ready to go into production thanks to the AMRC,” he commented.

The roof batten joint can join two roof battens at any point on the roof to save time and material waste. This made felting and lathing a roof quicker, but also safer as it eliminates weakening of the roof structure from trimming and patching battens that can lead to split batten ends and joint failure, said Johnson.