To allow the old building to provide a comfortable internal environment and reduce its energy use the walls, floors and roofs are being insulated. Given the importance and quality of the facades this is internal, which is challenging to detail. A moisture-open but air-tight system of lime plaster and woodfibre boards, Pavatex, is used as this minimises the moisture and condensation risks to the historic fabric.
At the same time the performance of the windows needs to be improved. Following a long study of the respective options before the listed building consent application, Heritage England and Rugby Borough Council approved the replacement of the old windows with new ones with thermally broken frames and double glazing.
This lining begins in earnest in the Power Hall, with the initial application of a levelling coat on the south wall and taping of services sleeves for the external lights. Briggs and Forester, the MEP contractors, find they need longer drills given the thickness of the old walls.
The plaster parge coat and insulation is installed after the new window frames and sleeves for services penetrations, so that a specialist joining tape can be used to lap these with the wet plaster, creating a continuous and durable air tightness barrier around the whole envelope.
The installation is complicated by the Power Halls expressed steel frame and crane rails. These are carefully sealed and all gaps filled prior to application of the insulation boards, so that the air tightness is maintained and no voids are left that would form a potential condensation risk.
In the Power Hall the former steel windows are replaced with slim aluminium frames, using a system with similar sightlines and profiles. In the Transmission Block the windows were generally timber, and these are replaced with new timber frames using the same mouldings and profiles but made deeper to accommodate the double glazing.
After a few weeks of communicating with the site team ...Read more
After a long period of dealing with all site issues ...Read more
Whilst lockdown is in place, we and Morgan Sindall are ...Read more
The Main Contract Works to build Houlton School have started, ...Read more
The last elements of the Enabling Works are now almost ...Read more
The southern screen wall and the old boiler room wall ...Read more
Coming back to see how the removal works have gone, ...Read more
In the former Transmission Hall the walls and soffits are ...Read more
The 1936 north wall of the link block extension revealed ...Read more
The new Main Entrance – demolition of the link block ...Read more
What a difference a fortnight makes – the western elevation ...Read more
First site visit, on a sunny day, with pristine Collins ...Read more