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How to install a root barrier so the lip stays visible

Updated: 22 October 2026

The usual failure is not a thin sheet. It is a sheet buried flush with the lawn, or an overlap opened by soil, so rhizomes walk out of the bed. This is how to install a root barrier: services first, then a trench shallower than the sheet is tall, then a sealed join, then a lip you can still see. Product ranking stays on the [root barrier comparison](/hub/garden-supplies/root-barrier). The RHS growing guide, Palm Centre’s install note, and HSE excavation guidance were checked on 20 October 2026. These rolls were not installed in a trial garden. Links to amazon.co.uk can earn a commission at no extra cost to you.

The usual failure is not a thin sheet. It is a sheet buried flush with the lawn, or an overlap opened by soil, so rhizomes walk out of the bed.

Our top picks

DeepRoot DeepRoot panels, 18 in × 24 in

Best overall

DeepRoot DeepRoot panels, 18 in × 24 in
7.5/10about £68.52
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West Bay West Bay roll, 20 ft × 24 in

Rank 2

West Bay West Bay roll, 20 ft × 24 in
8.9/10about £52.92
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aleawol aleawol roll, 6 m × 55 cm

Best value

aleawol aleawol roll, 6 m × 55 cm
7.4/10about £34.68
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On this page
  1. 1.Before the spade
  2. 2.Trench, lip, and slant
  3. 3.The join
  4. 4.After backfill

Before the spade

A bamboo trench is still an excavation. Private individuals can use LSBUD to ask member asset owners for plans before any dig. Those plans do not show every private pipe. The Health and Safety Executive’s excavation guidance expects you to locate cables rather than discover them with the spade. Powered digging close to a known service is a stop. The figure that guidance is cited for is about 0.5 m. If a trial hole shows a live service, stop. The same pause applies to a party wall, next door’s land, a tree preservation order, or Japanese knotweed. Do not use these depths as a knotweed method.

Trench, lip, and slant

Dig shallower than the sheet is tall. The RHS growing guide describes a trench of about 60 cm and about 7.5 cm of barrier left above the finished soil. Palm Centre sets the visible portion at about 10–15 cm and angles the top away from the bamboo. A 60 cm roll buried to 60 cm finishes level with the soil. Which titles can carry both numbers is the buying guide. Set the sheet as one continuous wall. Reviews of the HDPE rolls say the sheet curls until it is warmed or packed into the trench. The ANLEBUY bullets say to leave the roll in the sun for about two hours. Hold the top where you can see it, then fill. Rhizomes of running bamboo are often in the top 30 cm.
DeepRoot DeepRoot panels, 18 in × 24 in

Testsieger

DeepRoot DeepRoot panels, 18 in × 24 in
7.5/10about £68.52
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The join

The RHS guide asks for an overlap of at least 30 cm, sealed with mastic. Palm Centre asks for at least 0.5 m, closed with gaffer tape or a bolted fastener, with no soil in the join. Butting two ends is neither. Seal the whole height, including the lip. The West Bay and Gainspra bullets do not list a connector. If the listing has no join kit, the seal is mastic or tape you supply. Ribbed panels are a different join. DeepRoot’s pack uses a zipper, and the ribs face the tree, which belongs on the roll or panels page. One UK review snapped a panel with a mallet. Do not hammer the plastic into line.

After backfill

Walk the line before you call it finished. The lip should be visible all the way round, the slant should still lean away from the bamboo, and every overlap should be closed. Mulch and turf stop at the lip. Check again in autumn, which is the inspection Palm Centre suggests. Cut any runner that has reached the top while it is still on your side of the sheet. A barrier does not chase rhizomes already outside it. Stop when the trench meets a live cable, when the plant is Japanese knotweed, when a tree preservation order is in the way, or when the dig would affect a party wall.

Common questions

How deep do I dig relative to the sheet?
Dig less than the sheet is tall. The RHS figure is a trench of about 60 cm with about 7.5 cm of plastic left above the soil. Palm Centre leaves about 10–15 cm above ground. Measure the roll on the day, then mark the lip before you backfill.
How much plastic stays above the soil?
About 7.5 cm in the RHS growing guide, and about 10–15 cm in Palm Centre’s install note. The lip stays visible above soil, turf, and mulch. A sheet buried flush with the lawn lets rhizomes cross.
Do I slant the sheet?
Yes, if you are following the nursery method. Palm Centre angles the top away from the bamboo so rhizomes that climb the plastic surface on your side, where you can cut them. A slant with the top buried is not the method.
How do I join two ends?
Overlap them and seal the overlap. The RHS minimum is at least 30 cm, closed with mastic. Palm Centre uses at least 0.5 m, with gaffer tape or a bolted fastener, and no soil in the join. Seal the full height, including the lip.
What if the roll curls?
Reviews of these HDPE rolls say the sheet curls until it is warmed or packed back into the trench. One listing says to leave the roll in the sun for about two hours before cutting. Hold the lip in place while you backfill. Do not hit panels with a mallet.
Do I check for cables first?
Yes. Use LSBUD before you dig. Private pipes are often missing from those plans. Powered digging close to a known service, often cited at about 0.5 m, is a reason to stop. If you find a live service, stop.
What belongs on a yearly check?
In autumn, walk the lip. Confirm it is still above soil and mulch, that the slant still leans away from the bamboo, and that each overlap is still sealed. Remove rhizomes that have reached the top.
When do I stop and call someone?
Stop if the line meets a live cable or a pipe you cannot identify, if the plant is Japanese knotweed, if a tree preservation order is involved, or if the excavation affects a party wall or crosses the boundary.

Related pages

Root barrier for bamboo

Root barrier

Best root barrier: which HDPE roll to order first?

Bamboo root barrier: height, thickness, and length

Root barrier roll or panels: bamboo line or hardscape

Sources

Public UK sources for this comparison. Prices, stars and review counts are the amazon.co.uk listings captured on 19 October 2026. Page updated 22 October 2026.

  1. RHS: bamboo growing guide (retrieved 22 October 2026)
  2. RHS: bamboo control (retrieved 22 October 2026)
  3. RHS: trees near buildings (retrieved 22 October 2026)
  4. Environment Agency: RPS 178 (retrieved 22 October 2026)
  5. PCA: Japanese knotweed code of practice, November 2023 (retrieved 22 October 2026)
  6. Natural Resources Wales: Japanese knotweed (retrieved 22 October 2026)
  7. DeepRoot: root barrier installation manual, 2025 (retrieved 22 October 2026)
  8. HSE: excavations and underground services (retrieved 22 October 2026)
  9. Palm Centre: how to install bamboo root barrier (retrieved 22 October 2026)
  10. Consumer Rights Act 2015, section 11 (retrieved 22 October 2026)