What is Japanese Knotweed?
Japanese Knotweed (Fallopia Japonica) is a strong-growing, perennial plant. In spring and summer, bamboo-like shoots grow to 2.1m (7ft) tall. Leaves are up to 14cm (5½in) in length and the creamy-white flower tassels produced in late summer and early autumn reach up to 15cm (6in).
An amendment to the Anti-social Behaviour, Crime and Policing Act 2014 includes Japanese knotweed and other invasive non-native plants. The Home Office guidance note is available to download here.
Soils contaminated with Japanese Knotweed can be buried and encapsulated within a ‘fully lined tomb cell’ situated on the development site which prevents the very expensive need to transport the contaminated soil to a licensed landfill site.
A ‘cell’ allowing for a 2m burial depth is excavated, a puncture proof geotextile or protective layer of sand is placed and then Greenfix 600 Knotweed Barrier is deployed ensuring that the entire ‘cell’ is lined allowing for enough excess material around the perimeter to facilitate the eventual ‘capping’ of the cell. The contaminated soils are then placed within the ‘lined cell’ and then the ‘cap’ is placed and sealed to the overlapping excess edges to ensure the cell is fully sealed and encapsulated. A further deployment of puncture proof geotextile or protective layer of sand is placed and the area is buried deep enough to prevent any potential penetration of the area in the future.
Installed vertically around the perimeter of a development site to prevent the lateral ingress of roots.
Installed horizontally over the development area to protect roads, paved surfaces, floored areas and buildings.
Greenfix 600 Knotweed Barrier
Minimum 25 year service life once buried
Conforms to the Environment Agency’s ‘The Knotweed Code of Practice’ document