New mid-Wales school roof mimics surrounding mountains

January 2017

New mid-Wales school roof mimics surrounding mountains

THE roof of a new £5.4m BREEAM Excellent-rated primary school in mid-Wales has been designed using materials and contours to mimic its mountainous surroundings.

Ysgol Bro Dysynni near Tywyn features Welsh slate, sedum planting and a mix of angular and rounded contours across its 1,200m2 roof to reflect the landscape of Snowdonia’s southern mountains.

Prelasti EPDM waterproof membrane was supplied and fitted by AAC Waterproofing in Anglesey, who also created the green roof with leaky pipe irrigation system.

The new school draws pupils from a wide catchment area renowned for its natural beauty. As well as four classroom and a multi-purpose hall also suitable for community use, it features dedicated IT, library and science suites.

With a BREEAM Excellent design score of 74%, it features rainwater harvesting, biomass boiler and photovoltaic power.

AAC’s Prelasti EPDM was chosen for its 20-year guarantee and 50-year lifespan, light weight, durability, and its BREEAM A+ environmental rating.

Prefabricated in a controlled environment at the company’s Anglesey factory, AAC created 15 sections using vulcanisation, a technology that bonds together 1.2mm-thick Prelasti membrane sheets at a molecular level.

The tapered sections were packed as rolls for easy transport to site, laid on top of a vapour control sheet and Kingspan insulation board, and cut to fit.

A Centrix mechanical fixing system using heat induction was used to fix to the substrate, ensuring no punctures and enabling removal of the membrane sheets intact should the need arise.

As well as working around rooflights, roofline structures and solar panels, AAC was required to fit the membrane to 25-degree pitches as well as angular and curved flat roof areas.

A thin wildflower mix sedum from Welsh borders supplier Sky Garden was used in addition to retention strips for pitched roof coverings and leaky pipe irrigation. The works include a 12-month green roof maintenance contract.

In all it took two weeks to prefabricate the complicated roof shape and four weeks for a complete fit, including the green roof elements.

Ysgol Bro Dysynni was designed by B3 Architects and constructed by North Wales-based Wynne Construction. It opened in September 2013.