Lagg Distillery, located on the Isle of Arran in Scotland, is a new build whiskey distillery which opened its doors to the public for the first time in the autumn of 2019.The client was eager to create an iconic landmark and echo the contours of Arran with a roof scape that would blend into the environment. In order to ensure all expectations were met, Bauder worked closely with the architect, Denham Benn, during the design and specification of the project.

A metal roof deck laid on steelwork formed the structure that would incorporate a warm roof build-up with a lightweight sedum green roof finish to resonate with the landscape and withstand the prevailing winds.

The specification

To meet the project brief, the technical team at Bauder designed a bespoke roof solution for this project, combining our bituminous system, Bauder Total Green Roof System (BTGRS) with our lightweight, integrated, XF 301 sedum system.

BTGRS was specified for this project due to the systems’ special cap sheet that has been tested by the FLL to ensure long-term root resistance. It was also chosen for its longevity and heavy-duty, robust qualities.

Products applied

BauderGREEN XF 301 sedum system:

This light weight, all-in-one sedum system comprises a mix of over 14 species, and can be installed directly onto the BTGRS waterproofing without the need for further drainage and substrate layers. This system contains a moisture mat which retains up to 5 Ltr of water/m2, helping to retain water for the plants in pitched roof scenario.

Project challenges

The shapes of the roofs are complex, rising from 2 metres above ground level to 12 metres, the width of the roofs varying from 16 meters to 40 metres, and gradients ranging from 8 degrees to 31 degrees. On the steeply pitched roofs, the insulation and waterproofing are supported by mechanically fixed battens, these carry the weight of the system over the extreme slopes.

The building is perched on cliffs close to the Atlantic Ocean which face prolonged storms and gale force winds for many weeks a year. A unique sedum restraint system consisting of stainless steel retention strips and aluminium edge trims were fixed to the roof to hold the system in place and prevent wind uplift and slippage of the blanket. Due to restrictions with ferries, a delivery system had to be implemented that first saw materials to a holding place on the mainland, then meet the designated ferry to the island before finally being hoisted by crane to the roof.

Working in such an environment called for maximum focus on safety during the installation. A system of abseiling pulleys and fall arrest systems were set up on the sloped roofs together with wind monitoring and on-site instruction.

On completion of the works a permanent Latchways fall arrest system was installed. An irrigation system has also been commissioned complete with break tanks, pump, pipework and controller in order to provide a water feed to the sedum in times of drought to ensure the health of the living vegetation.

Bauder Total Green Roof System (BTGRS) with BauderGREEN XF 301 Sedum System

Advocacy 

Greenroof UK were awarded green roof project trophy for their workmanship on the inspiring Lagg Whiskey Distillery and Visitor Centre on the Isle of Arran. The finished roof emulates the look of a rolling hillside and cuts an impressive view against the backdrop of the Firth of Clyde.

Scott Dean, managing director at Greenroof UK Ltd:

“This project pushed the boundaries in terms of installation, logistics and environment; therefore, it is a tremendous accolade to have won this award which acknowledges the contribution of everyone involved.”