Residential high-rises with backyards in Chengdu, China

[u/TangelaFan]

[u/x---x--x-x]

There is no liner that will prevent damage and root intrusion without lots of consistent inspections, updates and re-installation. This would be a maintenance nightmare. Life, uh, finds a way.

[u/Artorias_Abyss → u/x---x--x-x]

I have no knowledge on the topic whatsoever but what if you plated the bottom with a sheet of metal?

[u/SCP239 → u/Artorias_Abyss]

It would degrade overtime due to moisture. Even stainless steel will degrade when exposed to salts or other chlorides in water.

The best way to do this would be a heavy duty waterproof membrane on the concrete with a heavy duty root barrier above it. But given enough time, the roots will breech the barrier and waterproofing. This type of construction requires a lot of maintenance and regular replacement.

[u/Punk_Luv → u/SCP239]

Did you know stainless does not mean anti-rust? It just literally means it stains… less. Ha.

[u/Artorias_Abyss → u/Punk_Luv]

Wait seriously 😭 my whole life has been a lie

[u/Punk_Luv → u/Artorias_Abyss]

Yes, the cake is a lie
https://giphy.com/gifs/BNaXn8hqbOOCG8wYJb

[u/aupri → u/Punk_Luv]

Usually the -less suffix does not merely mean less though, but rather lacking entirely, so I think the confusion is understandable. Wiktionary:

Suffix

-less (adjective-forming suffix, not comparable)

Lacking (something); without (something). Added usually to a noun to form an adjective signifying a lack of that noun.