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Don’t let Japanese knotweed add to delays on site

Don’t let Japanese knotweed add to delays on site


Long and costly delays on site have always been the stuff of nightmares for developers but now many across the country find themselves in the midst of a prolonged period of uncertainty over development schedules. But even where construction work has ceased due to Covid-19, there’s one job that developers should tackle now and that’s Japanese knotweed which is well into its rapid spring growth phase.

If knotweed is discovered on a site, it needs to be remediated within an enabling works contract, or very early in the build process. The good news is that treatment options have developed and improved considerably over recent years, meaning knotweed can be dealt with within a matter of days and, depending on the treatment method, huge landfill costs can be a thing of the past.

Herbicides can be applied over a period of two to three years, which will achieve an element of control, but the need to deal with the problem quickly and the fact that it’s impossible to be certain that the plant is dead without digging up the ground, means herbicide treatment is seldom the answer for developers.

Sifting and screening methods are proving an increasingly popular and cost-effective solution on development sites. We lead the field in this area with our unique and patented Xtract™ solution, which separates the knotweed rhizome from the soil on site, thereby avoiding the huge environmental and financial costs of consigning vast quantities of otherwise good soil to landfill and importing clean fill. It can be completed in a matter of days, produces zero waste and is the most environmentally friendly way of dealing with knotweed. Developers can also benefit from it being an on-site remediation method, being eligible for Land Remediation Tax Relief.

On sites where it is not possible to remove or kill all the knotweed crowns and rhizomes, for example where there are existing underground services present such as drainage and sewerage, or where the land cannot be disturbed as a result of a tree preservation order, there is a new option available. Plantex® Platinium is a new permeable membrane developed by global engineering firm Dupont, which can be laid horizontally beneath the surface of the ground to contain knotweed.

We’re still operating on development sites whilst adhering to the Government’s advice on social distancing. Contact us today to find out how we can help ensure Japanese knotweed causes no further delays so construction work can begin on your development site at the earliest opportunity.

Robert Spaceman

“We had a large stand of bamboo removed, thinned, contained and replaced. The customer service has been first class. Joe and Jason were fabulous and kept me well informed at all times”.