When is a modular flooring system not a modular flooring panel, when it’s also a modular wall and roof system.
Those were the words of a timber engineering and prefabricated offsite building consultant in alerting TTJ to AcerMetric’s panelised construction approach.
The Ongar-based company, which has just concluded a licensing deal effectively launching its flatpack system onto the mass market, believes its invention could revolutionise building both in the UK and abroad.
Seven years in development and testing the AcerMetric ‘beam and seam’ technology is the brainchild of David Appleford. He comes from a background in engineering and machine development, which saw him working on deep sub-sea structures for the oil and gas industry, and has applied know-how and methodologies from this field to the business of construction.
To simplify, speed up and make the building process more predictable, while delivering a cost effective and robust structure, the AcerMetric system essentially uses a common ‘panel’ design for every structural element; walls, floors and roofs and beams. It’s appropriate in more ways than one that the company describes it itself as a ‘versatile, elemental building system’. "It’s a new way of precision building, based on the engineering approach, and the methods used in car, aircraft and ship building," said Mr Appleford.
Clearly demonstrated on the AcerMetric website (www.acermetric.co.uk), the system comprises panels up to 3m long made up of a rectangular frame, with cross sections, expanded polystyrene insulation panels, and an internal skin of magnesium oxide board. "The composite make-up of these boards is what gives them their robustness and rigidity, delivering enormous structural strength to the end building," said Mr Appleford.
"They’re also light, with panels limited to a size so that the maximum weight is 100kg, which means they can be delivered flatpacked and you need just four people to lift them into place."
The AcerMetric system also features box-structure columns and beneath the ground floor and at each storey, ‘box beams’, which Mr Appleford describes as ‘long, thin versions of the panels’; a structural material, a skin and EPS insulation.
What makes the system so quick and easy to build is that integrated into all the elements is a 3D steel locking system. "Using a simple ratchet hand tool, this rotates onto itself, pulling the cassette panels onto each other and to the beams and columns, creating an extremely strong and air tight seal," said Mr Appleford, adding that specially designed windows and doors for the system also incorporate the fastening mechanism. "It’s like a child’s building block system, that creates a complete modular entity in any shape or style."
Underlining its strength, the fiveclassroom, 150-pupil Coppice Primary in Chigwell, the first school built using the system two years ago, had to meet the Secure By Design standard.
"Our current calculations show we could go up to three to four storey’s, but we believe we could engineer it to go higher," said Mr Appleford.
A damp proofing membrane goes onto the foundation, then the base structure of beams, stiffeners and insulation is constructed on top of this, followed by a further membrane. The composite floor and wall panels follow, then the beams and wall panels for the next storey or storey’s, with any form of roof structure, pitched or flat, topping the building off. And the whole shell of a three-bedroom, twostorey house can be completed in days.
In standard configuration, the finished building returns U-values of 0.18 for walls and 0.13 for floors and roof panels. "And by using a two-wall system we can achieve higher levels still," said Mr Appleford. "Sound insulation is also very good."
Externally, the building can be finished however the customer wants. The EPS can be directly rendered, or the walls machined to accept a brick slip system, or weatherboarding. Internally, the magnesium oxide board can be painted or papered, or finished with panelling.
The first prototype housing built with the system used pine for the frames and cross pieces of the panels and beams. For the school this was replaced with 27mm Metsä LVL.
He added that licensees AcerMetric is currently talking to abroad are all looking at the LVL-based variant, including some large-scale Asian businesses. "Further ahead they may use the bamboo version of LVL too, ‘lamboo’," said Mr Appleford.
