Butyl rubber pond liner?

Interested to know how you have dealt with the drainage?

Ditto on the pond liner.

Not trying to change your mind, but curious whats the benefit of a sealed veggie bed versus a draining bed with catchment underneath? What soil are you using to prevent anaerobic stagnation(?) at lower levels - is this a recirculating hydroponic system?

Floral, thanks for your suggestion. I did look at Butyl rubber but that is just not considered dangerous. There's a bit to go to a safe solution. I need to touch and smell it to make a decision. I'm one of those people who cannot stand a 'new car smell'.

I'm contemplating a simple wooden box standing above ground. The bottom will be furnished with something that provides a bit of slope. Drainage will be handled by one hole punched through the liner and drilled through the wood. I might choose to punch three holes and run a gutter underneath. So wood, something to provide sloping (styrofoam?), liner, coco liner, soil. That should be fine. If I can't effect this solution, then a large metal container with a metal pipe fed to the bottom and some kind of suction/pumping mechanism to reuse water.

Ryan, let's not get too deep on this. This is just a small planter for my balcony. I have lots of room but I would like the ability to bring it indoors to start early. I live in Toronto and May can still be quite cold at night. The balcony door is just over 2 feet wide. So my width is limited to 2 feet and length will reach 6 feet max. I need to line it to: 1) not worry about the wood, 2) not stain the balcony and 3) reuse water full of nutrients.

What about galvanized metal sheets? Let's assume these metal sheets are made in North America and not imported from Asia. Are they safe? Will they last? Will they have adverse effect on soil, such as overheating?

Ah, gotcha. Now i can visualize what you've got in mind.

I doubt you'll be moving a 2 by 6 planter. I have 2 that are 18 inches by 6 feet and they are basically permanent! Would need Superman's help to move them.

Perhaps consider several smaller wheeled (or each on a plant dolly) pots/containers, each with its own saucer.