ReX

Full height planters was the original plan, but then I gave up because these 60cm GRP custom made planters costed me a fortune (never considered in my life to spend almost 3k in planters) and making them 40cm higher would have increased the cost even more. Thinking about the hassle I am going through now, maybe it would have been better to get them 100cm. Do you mean pouring concrete? I have never done it but from a quick calculation I got scared by the huge amount of material I need to reach 40cm. I will need some guidance here. I have added few pics of the patio, better than my words (the old yellow and red slabs at the end of the new patio are all lifted, there will be grass there).

First post here... so hello everyone. I am not really a self builder, but in recent times I have done a lot of home renovation. My partner and I bought a fully renovated middle terrace Victorian house less than 5 years ago. In the house everything is new, but shortcuts were made, so I took this as an opportunity to learn how to do new things, fix the issues and at the same time upgrade the house specs. I would be happy to talk about the projects I did and post some photos, but I am sparing you an incredibly boring and long first post. Anyway, now that the house is done, I am focusing on the garden. The new raised patio (porcelain tiles on Eterno pedestals) is now complete. I need to build, on the two sides of the patio, solid bases on which GRP planters will sit. Each base must be 540cm long, 40cm wide and 34-41cm tall (the patio is levelled but the garden had a slight slope). The planters will be 60cm tall. The purpose of the bases is not just to support the planters, but also to avoid any lateral movement of the suspended patio (the tiles sit on top of the pedestals, they are not glued down). This is the reason I kept approx 44cm buffers on the two sides, instead of arriving full width to the lateral fences. I have already started raising one side, reusing the concrete slabs I've removed from the garden (weird solution but this was a quick way to dispose them and avoid heavy lifting, as I am working on my own...), but I don't have enough slabs to get to that height, so I am now thinking how to move forward and ensure it is levelled. How would you do it? I would like to minimise the amount of heavy material to carry through the house and I don't want to use wood. The only thing I can think of is: get to the approx height with 300mm*440mm aerated concrete blocks and then lay on top 180cm*30cm concrete gravel boards. But this won't get me to the 40cm width I need. These bases will be 3cm below the level of the patio tiles and fully covered by the planters, so the appearance of the surface doesn't matter. Happy to post pictures of the patio, if that helps. Thanks everyone and apologies for the long post.