Japanese Knotweed causes structural damage to walls, floors and foundations.
Knotweed roots penetrate up to 2 metres (10ft) below the surface and can spread for up to 7 metres (25ft) horizontally from the last visible sign of infestation. It crowds out native species and its clumps of stems provide a haven for rats and other vermin.
Knotweed breaking through tarmac
Knotweed was introduced to Britain in the 19th century as an ornimental plant. In the past 150 years it has spread widely around the UK and is now a problem in parts of the USA and Canada. It does not produce viable seed in the UK but spreads vegetatively by the actions of Man and animals. As little as 0.7 gram of knotweed can start a new plant. Broken pieces in streams and rivers have ensured its spread along many waterways.
Apart from structural problems caused by this vigorous weed, it can undermine embankments and, by its dense growth pattern, it soon crowds out all native vegetation creating a virtual “desert” underneath its canopy
In recent years there has been a steady realisation of the damage that Knotweed can cause and a number of Local Authorities (including Swansea) have appointed Knotweed officers to oversee the fight against this invasive plant.
Often a requirement to deal with knotweed infestation is a condition of Planning Consent.
Increasing concern over this countrywide infestation, and the realisation of the structural damage it can cause has caused mortgage lenders to shy away from properties that are infested or are only ajacent to infested properties !
Companies refusing mortgages (Oct 2009)
|Lender||Knotweed on property||Knotweed close to property|
|Abbey National||Decline to offer||Decline to offer|
|Cheltenham & Gloucester||Decline to offer||Decline to offer|
|Nationwide||Case by case||Case by case|
|Swansea B.S.||Decline to offer||Decline to offer|