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

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!