Japanese knotweed is a type of ornamental weed plant that spreads like wildfire and in its wake leaves behind devastating damage to the environment, biodiversity, gardens, human activities and buildings and property. 

Can Japanese knotweed damage buildings both on your property and that of any adjoining property is simply, yes? If one does not put in place sufficient measures to control and eradicate this weed plant, the resulting consequences can be immeasurable.

Based on the foregoing, in particular, homeowners have been on the receiving end of the damages caused by this invasive weed plant on their buildings and property.

Thus, to understand the menace this weed plant can cause, especially, to buildings and property the subsequent section of this piece will explore the dangers the weed plant poses and provide more insight on the same as conversed below: 

Japanese knotweed and buildings – damage to structures

Japanese knotweed has a tendency to creep through the walls of buildings mainly in search of sufficient sunlight as this is one of the components that it requires to constantly grow.

This genetic behaviour makes the weed plant extremely harmful because it will exploit the tiny cracks, especially those that are near the joints of doors and windows and forcefully penetrate through.

Although, as a homeowner, you may deem this to be less harmful, in essence, you should be worried because as the weed plant forcefully makes its way in and around the cracks, the structure will eventually weaken and if no repairs are done, this may lead to the collapse of the structure in the long-run.

To this end, the damage caused to the structures implies that homeowners will require setting aside extra monies to constantly conduct repairs which may be frustrating.

Can Japanese knotweed grow through concrete? - knotweed removal
Can Japanese knotweed damage buildings – yes

Japanese knotweed and buildings – damage to underground structures

Most buildings have underground water drainage pipes, electrical underground cabling, and water or gas supply pipes amongst others. All these underground structures face the danger of being attacked by the Japanese knotweed.   

You may wonder why but the reason is quite simple; Japanese knotweed, just like any other plant, requires moisture and sunlight for survival. . This natural element makes the weed more treacherous in its quest to seek moisture.

When it grows beneath the building where these underground structures are located, it is easier to find that the roots and stems of this weed plant have occupied the spaces in between the pipes leading to clogging or even their complete blockage.

In other instances, as the weed plant coils itself around these underground structures, this can easily lead to their damage.

Japanese knotweed and buildings – damage to fences/walls/boundaries

It is a common practice to find homeowners erecting fences around their property.

Such fences/boundaries most times are made of wooden or plant material that is meant to act as beautification hence may not be very strong to withstand heavy force because this is exactly what the weed plant brings when it comes into contact with such fences.

Considering that the Japanese knotweed, once fully grown especially from the ground up, can become very heavy, it can easily overwhelm lightweight garden walls and fences, especially where the foundations are not so strong or poorly constructed.

Walls and boundaries are susceptible to Japanese knotweed damage to buildings too
Walls and boundaries are susceptible to Japanese knotweed damage to buildings too

Japanese knotweed damage buildings and more

Notably, considering that the Japanese knotweed does not discriminate on its preferred location of growth, this poses a greater problem to homeowners of the possibility to deal with the weed plant once it starts creeping through the tiny cracks and occupying the inside of the house.

The weed plant can ascent up the house walls, making the interior unpleasant and uninhabitable if not dealt with urgently. Basically, this weed plant can go to the extent of scrubbing off the paint on your walls, creeping under your household’s items and making life a living hell.

Japanese knotweed damage buildings internally and externally as soon as it has an opportunity
Japanese knotweed damage buildings internally and externally as soon as it has an opportunity

Japanese knotweed damage to property garden

Taking into account that Japanese knotweed can grow to lengths of 12 feet, this means that it can become a menace if allowed to continue growing on your property.

More so, if the weed attacks your garden, the dense nature of its growth can impede the growth of any underground vegetation. Furthermore, the playing space will be limited as time goes by. What are essential means is that the property space will be minimized and the value it too.

 Japanese knotweed damage to driveways

The weed can grow in between the spaces, forming paves and driveways.

Although the damage may not at first be extensive if left unattended, this may lead to the expansion of the joints of the concrete and eventually result in serious damage.

In extreme cases, the weed can completely block such facilities’ usage. There are various causes of the Japanese knotweed lifting asphalt; thus, we cannot undermine its damage.

Japanese knotweed damage buildings above and below the ground
Japanese knotweed damage buildings above and below the ground

Japanese knotweed damage to the value of property

Recent studies show that the presence of Japanese knotweed in an area causes the value of the property in that area to depreciate depreciates based on the invasive nature of the weed and the unprecedented damage that is likely to result.

Additionally, very few people will invest in a property that does not guarantee good serenity, peace, and quiet free of an invasive weed such as the Japanese knotweed.

Taking into account that Japanese knotweed is dangerous to the environment and buildings; this aspect greatly contributes to the depreciation of property investments around an area affected by the weed.

Additionally, there are many emerging cases of mortgage lenders being overly reluctant to offer financial support to purchasers intending to buy such properties under the Japanese knotweed attack.


Based on the short-term and long-term damage that the Japanese knotweed poses to property and buildings, it is advisable to always use the most effective method to get rid of the weed plant at its earliest stages of development.

The invasive nature of the Japanese knotweed makes it lethal once it is allowed to overstay in any location. Importantly, when his weed plan attacks your personal space, you can use removal DIY methods that are cheap and readily available.

For instance, burning and burying of the weed plant, mowing, and cutting down the canes of the weed plant.

Want to know more about how Japanese knotweed damage buildings?

Knotweed Removal aims to provide the most up-to-date information, help and advice for YOU to make informed decisions. If you are unsure or uncertain about how to proceed, please reach out to us and we will gladly come back and advise you as best we can.

Governmental advice can be found here and the UK law covering the removal of Japanese Knotweed as stated under the Wildlife and Countryside Act 1981 can be found here.

The best means to contact us is via our email – hello@knotweedremoval.tips

Do not forget we have a library of blogs covering many areas relevant to Japanese Knotweed, our free downloadable How-to Guides and Product Reviews on the latest methods being employed to eradicate or remove Japanese Knotweed.

Knotweed Removal, UK

Bestseller No. 1
Bayer Garden 2 x Path, Patio & Drive Weed Killer & Watering Can Set - 3 x 8g Sachets per pack treats upto 75sqm - Kills Ground Elder, Nettles, Docks, Couch Grass & Japanese Knotweed.
  • This exclusive twin pack and 9L Watering Set is everything you need for clearing weeds from paths, patios and rives including areas of tarmac, concrete and block paving.
  • Kills tough weeds and their roots including: Ground Elder, Nettles, Docks, Couch Grass, Japanese Knotweed, Brambles, Bracken & Ivy.
  • Each box contains 3 x 8g Simple ready measured soluble doses and treats up to 75sqm. Apply at any time when weeds are showing green leaf and are actively growing.
  • Sold with our durable 9L or 2 gallon capacity galvanised steel watering can with removable brass rose. Colour cannot be guaranteed. Watering can will be randomly picked and despatched.
  • Keep children and pets away from treated areas until the spray has dried.
Bestseller No. 2
Roundup Tree Stump Weedkiller, Super Concentrate 250 ml
  • Kills ivy japanese knotweed, saplings, brambles and nettles to the root
  • Kills up to 16 tree stumps
  • Contains a reusable pipette for specialist treatment of japanese knotweed
  • Kills the roots so weeds don't come back
  • Degraded in the soil by micro organisms
SaleBestseller No. 3
Weedol 011005 Pathclear Weedkiller Liquid Concentrate, 6 + 2 Tubes
  • Unique dual action fomulation, kills weeds to the root and prevents new weeds growing for up to 3 months
  • Ideal for paths, drives and patios
  • No measuring or mess - just add water
  • Creates an invisible barrier that prevents new weeds for up to 3 months
  • Children and pets need not be excluded from treated areas (once dry)
Bestseller No. 4
RootBlast - RootBlast 360 Glyphosate Home Garden Weedkiller - 1L Bottle with Integral Measuring Device Pair - Includes Pair Of gloves - 1L Makes Up to 50L
  • WEED KILLER CONCENTRATE: Rootblast's strong weed killer is both super-concentrated and tough on most broad leaf and grass weeds. It's specifically designed to bring you the best results by using systematic herbicide technology. It targets weeds from the inside and kills them at their underlying roots, preventing any future growth
  • GLYPHOSATE WEED KILLER: For optimal weed control, Rootblast have created a concentrate weed killer that contains 360g/l of glyphosate. Glyphosate is a broad-spectrum systemic herbicide and crop desiccant that is used by famers. It kills and destroys the weed without affecting the crop. By using glyphosate, Rootblast's weed killer is stronger and more effective than most other weed killers on the market
  • GLYPHOSATE HERBICIDE: This powerful and effective weed killer is designed to target weeds such as dandelion, grasses, docks, nettles, willowherb, bindweed, woody brambles, tree stumps, ivy and more. After applying Rootblast's heavy duty weed killer, the first signs of weed control are visible when the weed leaves yellow - this can take anywhere from a few days to up to 2-4 weeks. From this 1 litre bottle of glyphosate herbicide concentrate, you can make up 50 litres of product when it's diluted
  • DOCK, GRASS & DANDELION KILLER: Alongside this industrial strength weed killer, you'll receive a pair of protective gloves as well as the integral measuring device attached to the bottle. The gloves provide you with protection to ensure your experience is as easy and safe as possible. The integral measuring device is an inbuilt measuring cup, simply remove cap and carefully squeeze the container until the cup is full
  • TOTAL PROTECT WEED GARDEN SPRAY: This easy to use product is available as a ready to use tough, concentrated weed killer that comes with a integral measuring device attached and protective gloves. Use by professional garden and farmers, this product can tackle your weed problem and kill the weed from the root - the ultimate weed killer!
Bestseller No. 5
Rootblast Glyphosate Weedkiller 4 x 100ml Concentrate with 5L Pump Sprayer
  • For use on unwanted vegetation and areas not intended to bear vegetation
  • Contains 72 g/l glyphosate for effective control of annual and deep-rooted perennial garden weeds, including grasses*, docks, nettles, willowherb, dandelion and bindweed. Also suitable for woody brambles, tree stumps and Ivy.
  • Coverage up to 66sqm per sachet

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