New Leviat 60-year warranted Stainless Steel Concrete Fixing Screw for highly insulated façades

Engineered connections specialist, Leviat, has launched an innovative concrete fixing screw that enables external wall insulation thicknesses of up to 270mm to be securely accommodated in brick-faced concrete framed structures.

Manufactured in 1.4301 (304) stainless steel, or high grade 1.4401 (316) stainless steel for additional corrosion resistance, the new Ancon CFS+ Concrete Fixing Screw offers outstanding long-term performance and has enabled Leviat to extend the normal 25-year warranty for 25/14 restraint systems using concrete fixings to 60 years – in line with other steel framed applications.

Developed in collaboration with façade fixing specialist, Certifix, the new fixing screw is the first of its type to be manufactured in 100% thermally efficient stainless steel throughout. It is designed for use with the popular Ancon 25/14 Channel to provide a fast and reliable fixing solution for highly insulated, next generation net zero carbon, BREEAM and Passivhaus developments.

Driving the outstanding performance of the new Ancon CFS+ is a unique stainless steel concrete screw that requires only a standard 45mm embedment into the concrete slab. The high strength component includes special welded teeth which facilitate tapping into concrete up to grade C50/60 with ease. Testing has shown the CFS+ to give impressive pull-out loads, particularly in higher grades of concrete where the fixing achieved a characteristic load of 10kN*.

As well as significantly reducing drilling time and preventing the time-consuming fixing failures which were previously common with higher strength concrete frames, the new screws are designed for use without compression sleeves, for easier fitting and reduced thermal transmittance.  Thermal modelling using a typical standard wall build-up with 150mm insulation has shown thermal transmittance can be reduced by 50% when using the new screws with Ancon 25/14 Channel as opposed to the current fixing screws.

Initially developed for Dunfermline Learning Campus, a major Passivhaus development in the UK involving a 250mm external wall stone wool insulation layer, the new CFS+ fixing screws have demonstrated an exceptional level of reliability, with zero fixing failures reported for the many thousands of screw installations made into the development’s C45 concrete frame.

Further development of the groundbreaking Ancon CFS+ screw is continuing in collaboration with Certifix, who, in the meantime, are available to provide site support and training for contractors as required.

For further information please contact us.   

*In C50/60 concrete with no close edges or close spacing.