Lagg Distillery

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


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.

Bauder Building Board

Project name:

Lagg Distillery

Project type:

New build


Isle of Arran, Scotland

Roof size:


Building owner:

Isle of Arran Distillery


Denham Youd

Approved Contractor:

Greenroof Ltd

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 meters above ground level to 12 meters, the width of the roofs varying from 16 meters to 40 meters, and gradients ranging from 8 degrees to 31 degrees. On the steeply pitched roofs, the insulation and waterproofing is 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.



System installed

Bauder Total Green Roof System (BTGRS)

BTGRS is a durable, root-resistant bituminous waterproofing solution for use with landscaping. The system uses SBS modified elastomeric membranes for superior performance and unrivalled reliability,  The PlantE capping sheetis tested by the FLL and proven to give long-term root resistance. The system is suitable for all types of green roof landscaping options. The roof is covered with the comprehensive Bauder guarantee for product, workmanship and design.



1 BauderPLANT E

A 5 mm heavy duty, root resistant, SBS modified elastomeric bitumen membrane featuring chemically treated bitumen. Tested and approved by the FLL, perfect to use underneath a sedum blanket like that of Lagg Distillery.  

2 BauderTEC KSA DUO 

Self-adhesive elastomeric bitumen underlayer with DUO lap technology and glass lattice reinforcement.

3 BauderPIR FA-TE

Flatboard insulation board, faced on both sides with aluminium foil for optimum thermal output. For this project, 140mm depth used to meet the required U-value of 0.16W/m²K.

4 BauderTHERM DS 1 DUO

Self-adhesive, SBS elastomeric bitumen air & vapour control layer with patented “DUO” lap technology to ensure thorough sealing of lap joints, even in lower temperatures. The product also features thermally activated bitumen stripes on its top surface to provide the bonding compound for the insulation boards. The product features a glass lattice reinforcement for strength and stability, great for supporting the rest of the system used on this project.


BauderGREEN XF 301 Sedum System with integrated water retention and filter layer


1 BauderGREEN XF 301

Sedum vegetation blanket instantly providing at least 90% coverage on an extensive green roof. Integrated water retention and filter layer.

2 BauderGREEN AL 40

40mm high perforated edge/drainage trim frames and retains the Bauder XF 301 sedum system.


Multi-functional drainage and filtration layer which prevents the roots of sedum plants from becoming waterlogged.

4  BauderPLANT E

Torch-on root-resistant capping sheet green



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”