Consisting of a series of octagons, the 4,250 m2 flat roof of Unit 800 at Aztec West is not only one of the most complex roofs in Bristol it is also one of the most securely guaranteed after being re-roofed with a BMI Icopal’s Torch-on system.
Built approximately 27 years ago for the then owners South Western Electricity Board, Unit 800 is a multi-level office block offering nearly 7,000 m2 of office space for rent over the three floors. The office block is now owned by Regional REIT and managed by London & Scottish Property Asset Management, which spent £6.5 million on a Category A refurbishment that was project managed by Trident Building Consultancy.
“The existing roof had reached the end of its usable life and required full replacement to provide a good quality waterproof covering as well as meet current Building Regulations” says Andrew Hill, Associate Director at Trident. “We were looking for a good quality high performance felt system with a long guarantee. BMI met this requirement with its 20-year product guarantee, good range of high performance felt products and its long-established reputation in the market.”
Andrew added he preferred a high performance felt membrane on this occasion due to the hard wearing nature of felt because the roofs will be regularly accessed for maintenance.
Installed by Mitie Tilley Roofing, the new roof consists of BMI Icopal Total Torch Vapour Control Layer, 120mm BMI Thermazone Torch-on Roof Insulation Boards in the majority of areas and tapered insulation for the remainder, Total Torch Vapour Dispersion Layer and charcoal Thermaweld FireSmart Mineral Capsheet.
“The technical support from BMI is always excellent,” says Matthew Goddard, Area Director, Roofing. “Tapered insulation was designed and detailed by BMI to create falls in the areas of the building that had flat decking, with sumps to the perimeter to keep ponding water to a minimum. Regular inspection visits by the BMI technician ensured that any difficult details were overcome quickly and effectively, ensuring a very high standard of work.”
Suitable for both new and refurbishment projects, BMI Icopal Total Torch Vapour Control Layer is installed beneath the insulation – controlling the passage of internal water vapour through the roof structure and acting as a weatherproof temporary finish before the final waterproofing system is applied.
Easy to handle, cut and install, BMI Icopal Thermazone Torch-on Roof Insulation Boards combine excellent thermal performance with dimensional stability and high compressive strength, while BMI Icopal Total Torch Vapour Dispersion Layer stops the blistering created by the build-up of water vapour pressure within the roof construction.
Shielding the roof from both spread of flame and fire penetration, Thermaweld FireSmart Torch-on capsheets are 30% faster to apply than traditional torch-on membranes and their mineral surface provides a decorative and solar reflective finish for the built-up waterproofing system.
Together these components construct a tough, premium roof that withstands weather and foot traffic and, when installed to BMI’s specification and by a Team Icopal-approved contractor, like Mitie Tilley Roofing, qualifies for a comprehensive, insured guarantee cover of up to 20 years.
Image: © Roger Donovan, Media Photos