ᐅ Renovation of a Terrace with Edging and Issue of Rhizome Barriers

Created on: 9 Feb 2024 16:08
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MHaiz23
Hello everyone,

I am planning to renovate my old terrace by replacing the old patio slabs with new ones and edging the terrace with curbstones (currently, there are no curbstones). However, I am facing two challenges where I would greatly appreciate your advice and experience:

  • Issue with bamboo and rhizome barrier: Right next to the existing terrace, I have planted bamboo that is contained by a rhizome barrier (see attached photo). My concern is that when dismantling the old terrace, the bamboo together with the rhizome barrier might shift towards the terrace. Additionally, I see a problem supporting the new curbstones with a concrete collar because the bamboo’s rhizome barrier is located directly beside it. How should one proceed in such a case? What techniques or tools do you recommend to ensure stability and keep the bamboo under control?
  • Different heights of old and new patio slabs: The old patio slabs are 8 cm (3 inches) high, while the new slabs are only 6 cm (2.4 inches) high. Assuming the base of the old terrace is still in good condition, would it be possible to simply add 2 cm (0.8 inches) of sharp sand or aggregate, level it, and then lay and compact the new slabs on top? Are there any risks that the new terrace might not be stable or level?
I would be very grateful for any tips, techniques, or experiences you could share with me. How do you best approach projects like this, and are there any special considerations or materials I should keep in mind?

Thank you in advance for your support!
Paved terrace with stone slabs; bamboo hedges on left and right, wet lawn in the background.
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MHaiz23
10 Feb 2024 21:23
Hi Jasmin, thank you for your question. Unfortunately, bamboo does require a rhizome barrier, and it is best to keep it in place.
Best regards
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Philfuel
11 Feb 2024 07:17
Just make the terrace a bit smaller, or move the edging stones slightly inward. That way, you'll have room for a backrest on the side facing the bamboo. The gap can be filled with soil later.
If the substructure is still in good condition (maybe do a small trial excavation), I don’t see any problem with simply laying gravel and leveling it.
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WilderSueden
11 Feb 2024 12:19
For a terrace, I now see less of a problem if, instead of the usual 3-5cm (1-2 inches) of gravel, there are occasionally 7 or 8cm (3 inches) at the end. After all, no particularly heavy loads are expected.
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MHaiz23
11 Feb 2024 14:36
Many thanks for your responses @Philfuel and @WilderSueden! That already helps a lot! I also really like the idea of making the terrace a bit shorter.

Do you have any suggestions on how to support the bamboo rhizome barrier while digging there? To make sure it doesn’t collapse? Or are there any other tricks? Since once it’s pushed out, I probably won’t be able to push it back in again.

I’m imagining something that could be clamped in place and then adjusted with a screw mechanism or similar… then I would gradually work on the back support in sections and let it set before continuing with the rest (or something like that)?

Thank you very much for your help!
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motorradsilke
11 Feb 2024 15:17
What kind of root barrier is that? We also have bamboo contained by a barrier, but it’s a 2 mm (0.08 inch) thick membrane, and the roots have grown through it completely. Nothing would change if you dug up one of the four sides.
If you’re worried, drive some sturdy metal rods (reinforcing bars) into the ground beforehand to hold it in place.
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MHaiz23
11 Feb 2024 15:29
motorradsilke schrieb:

What kind of rhizome barrier is that? We also have bamboo inside a barrier, but it’s a 2 mm (0.08 inch) thick sheet, and everything has grown through it. Nothing would change even if you dug up one side out of four.
If you’re worried, drive some sturdy metal rods (reinforcing bars) into the ground beforehand to hold it back.

Exactly, it is a 2 mm (0.08 inch) thick sheet. The bamboo was planted inside it 4 years ago. It’s possible that nothing will happen. But the idea with the steel rods is great! That’s how I will try it. Thank you so much, you have really helped me!