Architect: PRP Architects
Structural engineering consultant: Gyoury Self Partnership
Main contractor: Chorus Group Ltd
Roofing contractor: Mars Construction
Type of works: Refurbishment of appartment block using Ashjack curved roof and finished with the Ashzip standing-seam roof system.
The new Inspire Gleeson Homes, with its striking Ashjack curved roof, finished with the Ashzip standing-seam roof, has attracted the attention of buyers with its beautiful design situated at the heart of Crawley Town Centre, adjacent to the historic high street.
The Ashjack system was first developed in 1988 by Ash & Lacy. It was one of the first structural lightweight over-roof conversion systems in the UK, developed to overcome the problems of the 1960s and 1970s flat roof design failure to shed water and retain thermal insulation. Generally used for refurbishment, the needs of the design and the properties of the Ashjack system made Ash & Lacy one of the first choices for roofing.
As the Gleeson apartment block occupies a very prominent position on a corner site, and is the landmark building on a major route through town, PRP Architects designed curved roofs to create a contemporary image, whilst the low height of the roofing achieved a more traditional form of construction. Therefore, to achieve the look, structural engineering consultant, Gyoury Self Partnership used the Ashjack system as it ensured the bulk and form was agreeable with the planning officers in such a sensitive location. Another prominent feature of the Inspire Gleeson Homes is the highly glazed, barrel-vaulted bay on the corner, which creates a successful urban design feature at the junction of the two streets.
Unlike the usual lightweight joisted construction used for refurbishment, the Inspire Gleeson buildings have been designed with an in-situ, concrete slab at the upper level to provide a firm platform on which to bear Ash & Lacys Ashjack structural supports. CAD was used to design the curved roof beforehand. The roof was initially designed as a cold roof with an insulation overlay across the in-situ slab to ensure thermal protection.
In line with their total-envelope solutions and essential to the overall structure of the roofing is the Ashzip standing-seam roof which is secretly fixed around halters, and overlays the Ashjack framework. The Ashzip material is light, easy to handle and eliminates the need for penetrative fixings, increasing the effectiveness of weatherproofing.
Ash & Lacy offers a complete package as they also supplied the Ashfab fabrications for the Crawley Inspire apartments using polyester-powder coated specialist fabrications, aluminium flashing, curved flashings, aluminium standard and curved gutters to create a beautiful finish for Gleeson Homes.
Gyoury Self Partnership had previously worked with Ash & Lacy. The engineering consultant recognised that the curved framework had several advantages; not only does it look aesthetically pleasing, but the Ashjack frame on a flat-concrete slab also acts as a barrier to provide acoustic separation between the individual flats.
The framework complies with wind, snow loading and building regulations. Rick Potterton from Gyoury Self Partnership comments, 'In using this simple solution we avoided the expensive curved-structural steel trusses or portals spanning between the outside walls and also the complex detailing of taking the internal separating walls 150mm above the ceiling line. We would employ this technique again to form a curved roof. Ash & Lacy is clearly a competent firm; their technical service was excellent.'
The roofing contractor responsible for the project was Robin Harris from Mars Construction, he was pleased with the finish and with the relationship they have with Ash & Lacy, he sees it as, 'a complete package that offers a steel framework, roofing, flashing fabrications, gutter, rainwater pipes and steel-support structure. Ash & Lacys products are of high quality, the service is good, with a guaranteed warranty. They are also nice people to work with.'