Baggeridge claims that the system could triple the speed of wall construction, regardless of the weather. Walls constructed using the system will be cheaper, because they are lighter than those built using traditional brick construction, so a separate foundation is not needed. And because these walls will be thinner, covering less of the building's footprint, floor areas will be larger. But the real innovation, particularly with the current skills shortage, is that the services of a bricklayer are not needed to build the wall.
The system, called Corium, comprises a series of extruded brick tiles that can be made to lock onto a steel backing plate by simply tapping them into position with a rubber mallet. Rather than laying bricks one on top of the other, entire brick courses can be pushed into place. And if a brick has been tapped into the wrong position, or the wrong colour brick used, it can be simply removed by levering-out with a screwdriver. Completing the wall is then just a simple matter of squirting mortar between the brick tiles.
The system, which developed as a collaboration between Baggeridge, modular building manufacturer Terrapin International, and steel giant Corus, has taken seven years to evolve.
The inspiration behind the idea came from an initial meeting between Jim Edwards, Baggeridge's commercial director, and Nick Whitehouse, managing director of Terrapin International. Terrapin was looking for a tile-hanging system for its modular buildings. But Edwards had a better idea: he says he got "quite excited" when he realised it might actually be possible to meet Terrapin's needs using an extruded brick rather than tiles. This would give the appearance of a traditional brick wall but would use tile-manufacturing technology. Four years into the system's development, steel manufacturer Corus was brought on board to help in the design of the steel backing plate.
"We needed assurance from a steel manufacturer about durability," explains Phil Noble, Baggeridge's technical and design manager.
On site, the backing plate is the first part of the system to be installed. The plate is produced from plastic-coated galvanised steel in 2.4 m long strips, 75 mm wide, which have been produced with sprung top and bottom edges.
It is these edges that hold the brick tiles in position. For most applications, the steel strips will be laid horizontally, starting at the top of the facade and working down by clipping each strip to the one above until the facade is covered in a single blanket of steel. The steel can be attached to any framing system – timber, concrete, steel or even traditional masonry – for refurbishment projects. But for features such as soldier courses where the bricks stand vertical, the steel strips must be fixed vertically too.
Once the facade has been blanketed in steel, it is time to add the bricks. This is the fun part of the installation. Forget skilled bricklayers – all E E that's needed to transform the steel facade into a brick-clad wall is a pallet of bricks and an operative armed with a rubber mallet. The brick tiles are only 32 mm thick, but within that depth both their top and bottom faces feature a recessed groove. To install a brick, the operative holds it in position between the sprung edges of the steel strip. With one tap of the mallet the backing strip's sprung edges will lock into the groove on the top and bottom of the brick to hold it securely, so that whole courses of bricks can be installed in minutes.
The steel backing ensures the horizontal spacing between the bricks is consistent. Vertical spacing is judged by eye. Baggeridge did try producing a wooden spacer to help the installer keep this gap consistent, but field trials proved this unnecessary as the installer's eye was reliable enough.
This system will give architects additional flexibility to create new and exciting brick facades. Because the bricks are simply tapped into place, any bonding pattern can be created just by varying the position of a row of bricks relative to the one above or below. The same method will also allow patterns to be created or even decorative brickwork designs to be produced easily. For particularly tricky designs, the bricks could even be mounted on the backing plate off site in the controlled environment of a workshop, for example. At this stage in the wall's construction, if a brick is the wrong colour, or if it is blemished, then it can simply be removed and replaced by levering it from the backing-steel's sprung edges. This is done by inserting a screwdriver behind the brick to prise it off. It is then easy to tap in a replacement.
Once a quality check has been carried out and the brick facade has been given the thumbs up, it is time for the mortar. Forget the need for a trowel; mortar is simply squirted into the gap between the bricks using either a mechanical pointing system with an electronic mortar pump, or a hand-held gun similar to a mastic applicator. Baggeridge claims that the mechanical system allows a two-man team to point a three-bed semi in a day. Once the mortar has cured it is given a "bucket handle" finish, by dragging a curved trowel along the joints – the same way mortar is finished on a traditional brick wall.
The mortar serves two purposes: it completes the facade's traditional brickwork appearance and it secures the bricks in place. This is the only part of the facade's construction that is weather dependant. However, "because the mortar application is not on the facade's critical path, there is an element of flexibility as to when, precisely, this operation is carried out", explains Noble.
Edwards says every time the system is shown to somebody in construction another application is discovered. For supermarkets, offices or hospitals, for example, where a brick-built facade is often a pre-requisite for planning permission, "the system offers the contractor the duel benefits of both creating a weather-tight envelope early in the construction programme using the steel backing, and taking the brickwork off the critical path". For volume housebuilders, the system will introduce modularisation into the build process, speed up facade construction and remove the need for skilled bricklayers. And for schools, medical centres and medium-sized office accommodation, entire wall sections could be prefabricated off-site to speed up construction.
The brick tiles are available in a variety of colours and shapes. Because the bricks are produced by extrusion, Noble says, "specials can be produced simply by changing the extrusion die". For architects looking for something really different, the company is investigating the possibility of producing bricks with diagonal edges, or even producing the backing strips from stainless steel, for use without mortar, so that specifiers will be able to create a brick wall with glimpses of steel instead of mortar.
Cost consultant Davis Langdon & Everest has assessed the system. According to Edwards, its studies for a standard project showed a cost reduction of 17% over a wall built using traditional construction. "And that's even before savings on the building's structural frame are taken into account," explains Edwards. Baggeridge claims the system is less wasteful than using brick slips, which involves cutting the face from an existing brick and then throwing the remainder of the brick away. "It is ridiculous to make a brick, cut the face from it, throw away the waste, then glue the cut face onto a backing," expounds Edwards.
Wind loading tests by BRE apparently show that the cladding is suitable for use on any building up to 10 storeys high. In fact, the company is so confident in the system that it is offering a 60-year guarantee.
Initially, Baggeridge plans to trial the system on a variety of projects to iron out any teething troubles. Once that is done, the company will be offering a supply-and-fix, one-stop shop by working in partnership with approved installation contractors with cladding and bricklaying experience. So put down that trowel and pick up a mallet – the brick wall is about to move into the 21st century.
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