New school roof doesn’t fall flat

A new Kalzip ‘Flat Pan’ roof has been created for the landmark Orchard Brae School in Aberdeen.

Over 3,000 sqm of aluminium standing seam profile has been used to clad the facility, which has been built to assist local children and young people aged 3-18 who require Additional Support Needs (ASN).

Roll-formed onsite, this is the first project in the UK where Kalzip’s ‘Flat Pan’ profile sheets have been installed.

The school was designed by jmarchitects and constructed by Ogilvie Construction for Aberdeen City Council in partnership with hub North Scotland.

The architects originally hoped to use a zinc cladding but, according to Kalzip, the “lightweight, long-lasting and highly robust” Kalzip aluminium system proved more cost-effective. Kalzip also supplied the new ‘Flat Pan’ profile standing seam sheets High Performance Colour coated to RAL 7005 to satisfy the desire for a traditional zinc clad appearance.

Kalzip said the liner roof system, which was installed by Aberdeen-based Fowler McKenzie, achieves a U-value of 0.20 W/m²K.

“We worked very closely with jmarchitects and Kalzip’s technical team right from the early detail design stages and we’re delighted to have been able to play such a significant role in the construction of this impressive new educational facility,” said Phil McKenzie, managing director of Fowler McKenzie.

Most of the building is covered with pitched Kalzip roofs with valley gutters running between them. The pitch of the roofs range from 25° to 45°, the steepest being flat-topped with a combination of Kalzip sheets and large double-glazed rooflights to allow natural daylight into the school’s swimming and hydrotherapy pool areas. Elsewhere, “penetrations” were made in the sheets to accommodate smaller rooflights including over 60 Velux units.

In certain areas around the perimeter, the roof lines have been extended by continuing the ‘Flat Pan’ cladding sheets down to ground level. This was achieved by incorporating a composite lined insulated gutter system into the roof just above eaves level before disguising the gutters behind a bespoke fascia flashing. Kalzip explained that the cranked eaves were created by welding short angled sections of Kalzip to the tops of the vertical cladding sheets and then post-painting the welds to produce a “perfect” colour match.