Having over 30 years experience in the stone industry, recognised a number of years previous that the building techniques and composition was changing considerably with new regulations and commercial demands. Lightweight rapid construction methods began to dictate a change in certain products with traditional stone being one of them. Stone is not a product that can be compromised by simply using thinner thickness’s to make it lightweight, it’s composition changes from stone to stone and with the many thousands of types available worldwide, therefore the current BS EN 8298 and BS EN 1469 must be adhered to for safety, performance and fit for purpose compliance.
The above mentioned codes of practice made provision for these building technique changes by permitting the use of systems where a product development could be independently tested and assessed to prove that it was fit for purpose and complied. Aerolite was developed using stone veneers reinforced by an aluminium honeycomb cassette panel on to a designed aluminium rail installation system. This was a stage one development that proved very successful in the commercial buildings where lightweight technology was used for reducing on site programme times. The aluminium rail system permitted an installation prior to the panels arriving on site allowing a retro fit of the panels thereafter. This has proved very popular on developments such as retail units, student accommodation and residential, these types of development are regarded as quick profit return for early entry. This system is IP covered as Aerolite Ultralite.
A stage two development was initiated for granite as it was the most costly version of natural stone in the market, this time a system whereby the granite could be reduced in thickness by 60% through a means of reinforcement. A system developed by heating and applying an epoxy composition to fill the fissures etc exposed by the heat process and thereafter whilst the epoxy and granite are still warm , a fibreglass matt is fused to the rear of the panel as further reinforcement. Again we developed an installation system similar to the Aluminium cassette system and also with undercut anchors. This greatly reduced the cost of granite and the installation system facilitated a façade contractor installation against a stone mason which whilst reducing the site installation method also reduced further the labour time and cost. Again all was tested to ensure fit for purpose and compliance with the current BS EN codes of practice. This system is IP covered as Aerolite granite.
A third stage development was initiated to produce a further cost saving on the limestone and sandstone finishes, the BS EN requirements on these stones is much more comprehensive in fulfilling and we took this into account when developing this range. An Aerolite granite reinforcement was used for the sandstone and limestone veneers, this meant that stone to stone compatibility greatly reduced and thermal movement differential between the granite and stone. As with both other systems we were also able to produce preformed corners which were filled and dressed to represent a solid piece of stone for aesthetic solutions on site. The Aerolite granite has a tested performance to ensure BS EN compliance and we further carried out de-bonding tests between the granite and the stone. This system is IP covered as Aerolite Stonework.
We are highlighting this development to ensure clients that all our systems are compliant and have a history of use. There are new suppliers coming to the market all of the time and it is confusing for contractors, surveyors, architects, clients and local building control; to understand the compliance of the products and systems of the new companies. We are experiencing companies claiming that there stones are lightweight and have a reinforcement when the reinforcement plays no part in the materials improved performance. The MPA of the proposed stones flexural strength is not being taken into account when calculating the stones required thickness nor fixing positions. All of the reinforcement of the Aerolite systems have been fire tested as fires can spread quickly in the ventilated void, as was demonstrated by two fires in Dubai since the new year. A fire certificate is essential as most of the netting claimed to be reinforcement is plastic and the GLUE used to bond it to the back of the stone is normally very flammable. Therefore our advice is to check and see the certificate before approving and them being liable for not having checked in the event of a fire or the materials integrity being also compromised and pieces of stone falling out into the street and endangering people’s lives.
When in doubt ensure that the current BS EN are complied with and that you have proof.