Lagg Whisky Distillery green roof irrigation was completed in 2019 and is a large, modern distillery that uses traditional production methods. It has brought back whisky distilling to the southern coast of the Isle of Arran for the first time since 1837. It is open to the public for tours and tastings, with people travelling from all over the UK and abroad to visit.
The Distillery Building
Lagg Whiskey Distillery green roof features a substantial green roof of a complex shape. The roof rises from just 2m above ground level, right up to 12 metres high, with gradients ranging from an almost flat 8 degrees to a very steep 31 degrees. The roof width also varies substantially, ranging from 16m wide to 40m wide. The green roof was specifically designed to blend in with the landscape of the Isle of Arran, not only reflecting its colour from above, but even its rugged contours.
The Green Roof Project
Access Irrigation were responsible for the design and supply of the complete green roof irrigation system for watering the whisky distillery green roof. The system was fully automated, using a Heron Ma-6 irrigation controller. This controller has a large digital display for easy, accurate programming and a very high level of reliability. The controller features a pump freeze facility, which in conjunction with a float switch will suspend the programme in the event of a failure in the water supply. To prevent operation in wet weather a rain sensor was included. A Cat 5 pump & tank unit was used to create a pressurised water supply and to comply with the Water Regulations regarding backflow prevention. Solenoid valves were used to split the system into sperate zones, to allow each zone to operate at a separate time, thereby enabling good water flow and therefore efficient watering for each zone. The solenoid valves were connected to the controller via signal cable and connected to the pump & tank unit via supply pipe. Both the controller and solenoid valves were mounted on a metal plate for security, being housed in a plant room with the pump & tank unit.
Each solenoid valve is opened and closed in sequence by the controller. When the first valve opens, the pump will detect a drop in pressure (due to pressure release from the open valve) and will begin to operate to boost the pressure back up again. This will cause water to flow through the first (now open) solenoid valve to water the first zone. The controller closes the first valve, and immediately opens the next valve in the sequence. Once the last valve has closed, the water flow will cease, pressure will build again, and the pump will stop operating.
The Green Roof Irrigation
The green roof irrigation system was split into a total of 6 zones, with the green roof being watered using Permadrip-Pro dripline, with a dripper spacing of 0.3m. Permadrip-Pro is a brown coloured dripline designed for landscape irrigation with a 16mm pipe diameter and a wall thickness of 1.2mm. The 1.6 L/h drip emitters are pressure compensating, ensuring uniform output over a wide pressure range and include a built-in anti-siphon mechanism, to prevent dirt being sucked into the drippers at the end of the irrigation cycle. These features make it ideal for sub-surface use and for use on sloping sites. The emitters also have a large inlet filter and unique, continually self-cleaning design, giving excellent resistance to blockages. The dripline was laid out in rows along the width of the roof, with each row positioned 3m apart to ensure even, efficient watering.
The Result – a roof for all seasons
Our project has resulted in a thriving, natural and low-maintenance green roof which blends perfectly into its surroundings. We are delighted with the result and are proud to play our part in helping to develop roof irrigation systems for new, modern buildings like Lagg Whiskey Distillery green roof, whilst simultaneously maintaining the unspoiled beauty of remote areas like the Isle of Arran.
