INCA Case Study: Millbrae & Glen Courts, Coatbridge

​Built in the 1960’s, Millbrae & Glen Court are 2 x 14 story Wimpey No-Fines tower blocks of Leggat construction, spanning 7000 square metres of living space  There was a problem of thermal efficiency throughout the buildings as well as the projected lifespan of the properties which needed to be addressed.  Following a refurbishment in 1993, these high rise also had non-compliant rainscreen cladding that had to be stripped before any work could begin. Removing the rainscreen cladding revealed a steel-framed area at roof level, and weakened fixings in the concrete balustrade panels.

Leggat construction includes a type of autoclaved aerated concrete called Siporex, as well as brick and block and reinforced concrete cavity walls. This type of concrete is often brittle, and known to crack in wet conditions, which can expose steel work.  Combined, these issues can result in corrosion and cracked concrete, affecting the structure of the building.

The buildings were both designated as defective, with the structural integrity being brought into question, along with water ingress, wet rot, condensation and algae. 

Solution & Specification

The client’s requirements were that the buildings met the PAS 2035 standards, with BBA certification, and that the U-Values were dramatically improved.  All whilst observing budget constraints and building regulations, as well as the conservation and heritage considerations that had to be observed.

A structural survey revealed the existing cavity wall was in poor condition, and that a standard EWI system would not fully support the building. Structherm’s Hybrid EWI/SEWI (Structural External Wall Insulation) system was chosen as a cost-effective way to update these buildings, to provide extra strength where needed and standard EWI in more stable areas.

For this project, Structherm’s Hybrid EWI system incorporates a 110mm mineral wool standard External Wall Insulation to the gable walls and 125mm structural panels to the front and rear elevations. Combined, this approach effectively moves the dew point to the outside of the new render resulting in a warmer, drier environment within the properties.

Structherm’s specification included additional structural steel work supplied by specialist fabrication companies.

Additional structural steel wind posts were required for the top storey of the buildings. Our design team worked with the client to provide a clear idea of what was needed.

The End Result

With the U-value significantly improved from 0.59W/m2k to 0.26W/m2k, the housing now offers tenants a comfortable environment to live while also saving on energy/heating, thus reducing the carbon footprint of the properties.  Plus installation of a BBA approved system of mineral wool which is A2 fire rated.  The aesthetics of the buildings have been upgraded and improved remarkably, which has also extended the design life of the properties.  All this was done without the need to decant any tenants, offering them a huge benefit of going about their daily lives without the upheaval of having to move out of their property.

The use of Structherm’s SEWI transmits loads directly back to the structural floors, all whilst benefiting from the speed of installation.  The innovative Hybrid system is a cost-effective solution for thermal and aesthetic upgrading of non-traditional housing.  Another testament to the experience and expertise of Structherm.