Derby Museum & Art Gallery – IKO Permaphalt System

Project description

Derby Museum and Art Gallery, located in the heart of the city, is home to a range of culturally significant collections, including the world’s largest collection of work by the 18th Century artist Joseph Wright of Derby.

The building was established in 1879; designed by Richard Knill Freeman and given to Derby by Michael Thomas Bass. An extension was built in 1964.

The roof had come to the end of its serviceable life and required a complete strip off and reinstallation. The roof had been previously overlaid several times but each time the roof had failed before the expected life expectancy.

The client wanted the most robust and durable roofing system possible, as there was £70million worth of priceless paintings below the roof.

Solution and installation

NRA chose to partner with IKO to install a thermally improved mastic asphalt system as the company had the technical knowledge to assist on the complex design elements and offered the resilient, long-lasting products needed to give the client the peace of mind they were seeking.

The building has a number of roofs cascading from upper to lower areas, as well as a highly unusual, pitched mastic asphalt roof, adding a level of complexity to the design and installation process.

The existing pitch enabled an IKO enertherm MG board to be utilised, mech fixed using marine plywood and expanding metal. A tapered IKO enertherm MG board scheme was designed and installed to the flat roof areas.

This was complex, as all areas had to achieve the client’s target u-value, while maintaining the integrity of the building and minimising impact on existing details. The roof areas were then drained towards internal outlets and weirs.

A new ballasted man-safe system was installed to ensure all future roof maintenance can be carried out safely. IKO Permaphalt, a polymer modified mastic asphalt solution, was used to create a long-lasting, durable roof that met the client’s requirements and helped bring a new lease of life to a well-loved local institution.