Structherm systems were chosen for the ongoing planned maintenance programme as Rhondda Cynon Taff Homes (RCT) needed to externally refurbish over 70 non-traditional “Woolaway” precast reinforced concrete properties.
They wanted a cost effective external refurbishment solution that would overcome the structural defects associated with the failing concrete columns and panels and bring the properties up to current Building Regulations in relation to thermal efficiency requirements.
Having used Structherm systems on other non-traditional housing stock RCT once again opted to use our Structural External Wall Insulation system. The project which was split over two sites in Aberdare was awarded to a local contactor Thomas CMS Ltd who undertook specialist training from Structherm to become a registered installer.
The Woolaway house type was designated by the Building Research Establishment in the 1980’s as inherently defective due to numerous structural defects. These defects include cracking in the precast concrete columns and precast reinforced concrete (PRC) panels due to high rates of carbonation and low levels of chloride in the concrete which corrodes the rebar and then spalls the concrete.
The properties, which were built in the 1940s, were also losing heat due to their lack of insulation, leading to high fuel costs for residents.
A standard External Wall Insulation system was ruled out because it would not have resolved any of the structural problems associated with this property type.
The GPL125 panel measuring 2.4m x 1.2m was specified which incorporated a 105mm thick Enhanced EPS insulation core.
The panels were fixed to the concrete columns, without requiring any fixings going into the thinner PRC cladding panels. Specially selected fixings and washer plates were used before being mechanically clipped together to provide a rigid, continuous envelope around the houses.
To complete the system Structherm Fibre Reinforced basecoat render 14-16mm thick was applied followed by 8-10mm of dash receiver and a decorative dashing aggregate.