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[Radium]

I have little space, and thus I'm recently planning to use my rooftop as well for growing my green friends.
But I'm an student right now, and I live on a tight budget.
I don't like the idea of just placing some containers on the rooftop and call it a rooftop garden.
I want to prepare a real raised bed, using the cheapest materials, and totally safe for the rooftop (regarding water leakage)
My rooftop floor is made of Asphalt, and if there be water on it for extended durations, it will leak into the building and wreck the house.
Got any brilliant ideas?

I was thinking about using cardboard as the material for making beds/containers.
But need to find a glue-ish material for applying on it, to prevent the cardboard from rotting after a year or two.

Any ideas?

[Chicsa]

You can Poly the cardboard, but I think you'll have to reapply it.

We made cardboard furniture in one of my architecture classes, they can be quite strong but you have to laminate really well.
You still would potentially be dealing with water leakage however. Maybe figure out a water recycling system where your excess water drains into a bucket that you can then re-use

Green Roofs are a pretty complicated system

1 Like Roze likes this.

[BubbleCat]

I think cardboard has that one disadvantage: If any water leaks in it suddenly looses most of its strength. So maybe going with plywood and the likes is the way to go, I would consider contructing the floor and borders of the bed and lining it with pond lining sheets. They are made to contain water, easy for them to contain moist soil. Just make sure you have no sharp edges or points under it so it doesnt rupture, if in doubt use a layer of felt under it to protect it.

You should investigate how much bricks will be for you, bricks run cheap, have asthetical value (at least for me) and lend themselves to very intuitive construction. Durability is given, again: line with pond sheets.

Maybe you can substitute the pond lining with other plastic sheets for example the white black sheets... at higher risk.

Sadly its hard to get around using any plastic if you want it affordable and waterproof, only things like concrete (and maybe paint) will help you, or a carefully applied layer of epoxy on your concrete / bricks / cardboard / plywood.

Lets see what you stick with in the end.

1 Like Chicsa likes this.

[Chicsa]

Concrete Masonry Units (Blocks) I think were used for hydroponic troughs in Cuba, now are simply soil planters for urban agriculture. I think its called Organicopos?


This isnt it but one disadvantage is weight, blocks and bricks are heavy.
You still need to do as BC said however, concrete is porous and will leak, I suggest a water-reusage system still

1 Like BubbleCat likes this.

[chamomeleon]

I would check with your landlord to see if it's allowed, first.  Other than that, plywood is light, cheap and customizable.  Just waterproof the living hell out of it and you'll be fine 

1 Like dEEcor likes this.

[BubbleCat]

Or you come up with a floating design somyou can monitor the runout. If its not much it will evaporate within a few days and it doesnt need to be much, any runout suggests youre done watering. Also the whole thing wont get waterlocked ("closed container gardening"). So the best would be: Either seal everything but incorporate a runoff in your design, maybe one that allows you to collect and reuse water, or put it on stands and just ket it run on your roof where it evaps.

Why assume theres a landlord ?

[chamomeleon]

Landlord, housing manager, building manager, whatever   

And although container gardening isn't the desired outcome, I would like to point out that it is portable.  What happens if you move?

Just my 2 cents 

[BubbleCat]

Was just meaning maybe and hopefully Uranium is all those in one person.

1 Like Radium likes this.

[chamomeleon]

Well, in that case, ROOFTOP GREENHOUSE!!! 

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[Radium]

I'm living in a 4 story building.
There are 3 other families living here besides me.
I asked all of them, and they are very happy and eager to see the outcome, and called it a brilliant idea.
And also I'm literally the boss of rooftop, no one goes there without my permission (The door is locked, and the only person with keys is me).
And I don't plan to move anywhere, I'm doing just fine here already 

I would love to someday upgrade the bed into a greenhouse, and I guess it wouldn't be hard, it just needs some PVC pipes and "clear plastic membranes" (sorry don't know what you call these).

[BubbleCat]

For a greenhouse you'll most likely want to use Polycarbonate ribbed panels and a wooden or metal frame. Isnt your place rather hot anyways ?

You should consider a rainwater tank on your roof to minimise tap water use.

1 Like Radium likes this.

[Radium]

We have hot summers, but also very cold freezing winters, which kills any unprotected tropical plants.
A greenhouse will come very handy, especially for growing cacti without worrying about frost.
The rainfall tank idea is indeed very nice.

BTW, is MDF a suitable material for building the box on its own? I mean no other material applied to it for water-proofing or rot prevention.

[AcaciaAve]

I did a rooftop garden last year on a $150 budget.
Make sure you're stocked on seeds, create a shade canopy.
I would set a kiddie pool(if available) up and throw your pots in there, or better yet, convert it into a raised bed.

There were a few places where you would climb up to the roof using a ladder and little niches were built almost like attic space where the sun would still shine on. I planted a ton of Phalaris in soil and that ended up collapsing through that little niche. Good thing the building was already in poor condition otherwise it would have drained my finances fixing it.

On the roof we had Campsis Radicans, Corn, Mucuna Pruriens, Arundo Donax, Acacia Berlandieri, Opuntias, and some Safflower among many other things. You have to be able to water/mist daily.

Another idea would be to create a trellis of sorts that vines could climb on. That would at least give you something to grow whilst constructing the garden.

Hope that helps.
Best of luck on this

[chamomeleon]

Kiddie pools would definitely be good, since they're waterproof.  You might be able to use big plastic tubs/totes, but that might be a bit expensive. 

[oplopanax]

Kiddie pools sound good.

I don't know about waterproofing, but I have made some very nice raised beds for free out of pallets. You can often dumpster them behind grocery stores & they are easy to turn into all sorts of things.