If you are going for building a rooftop garden to an existing roof, you’ll need an engineer and an architect to review your home. If you are in the US, this will almost certainly get required by your local building code. This is not something you’ll likely be able to hide from code enforcers either, as it is on the top and exterior of your home. Regardless, this is a huge safety issue. Green roofs can be very heavy.
The weight of the vegetation, soil, and drainage system can easily weigh more than the entire existing roof structure. The average roof does not get designed to support this much additional load without reinforcing. If you do need to strengthen your roof, you’ll likely need a permit and engineer to design this reinforcing. Carpenters should not be designing, and engineers shouldn’t be doing carpentry, that is just how it is. Not using an engineer invites a lot of trouble as you are breaking the law and risking damage to your home and injury to yourself.
As for the actual installation. If you have a wood frame roof, it will likely need to reinforce, and then you’ll need to install a green roof membrane and drainage system. There are complete green roof systems that can get purchased for this specific purpose. I would recommend going in this direction as it is a proven and optimized approach.
Building A Rooftop Garden With Some Ideas To Rely On-
Wait. You cannot start a garden in a place that isn’t waterproofed, with adequate drainage.
Preparation of the site- If you have nothing but concrete, you can use large pots with waterproof saucers. Make sure your pots do not come of plastic, which breaks down in the hot direct sun but instead use high fired ceramic pots and saucers. But if it freezes where you live, then use wood pots or barrels with saucers to collect watering overflow, because ceramic will crack in freezing weather. You will have to work out waterproofing so you do not destroy a building under your plants –. Be sure the landlord gives you the a-okay. Also, be sure no extra water will pool anywhere. You will want excellent drainage to avoid rot, mold, and unwanted proliferation of bugs, like mosquitos.
Eggshells-. Start saving hard-boiled eggshells now. Separate the albumen from the hard shell. You will want to use eggshell calcium to augment your soil if you’re going to grow calcium-loving fruits and vegetables.
Some More To know-
Source your soils, plants, and seeds- Start looking for a source for heirloom seeds and organic seedlings if you plan to consume nature’s bounty. But don’t buy even one seedling until you have first prepared the pot to plant it in.
Also, keep an eye out for rich, organic soil. Depending on what you grow, you may need to augment the soil to meet the unique needs of the fruits and vegetables you want to be planting. Do research on each plant you want to grow and then provide and prepare the best soil for each plant and designated pot.
Tomatoes- For example, tomatoes like sandy soil which drains and dries quickly, and most indeterminate heirloom organic varietals need pots with a 20+ inch diameter x 25 or more inches deep. I find I get bountiful flowers on tomato plants about a week to ten days after adding pulverized eggshells. Tomatoes love calcium.
Other easy to grow veggies and herbs growing on my balcony in pots include lemon trees, lavender, green onions, parsley, chives, thyme, rosemary, mango tree, grapevine, green pepper, blueberry, raspberry, strawberry, pomegranate trees.
When everything you have purchased and prepared is ready to plant, pick up those seedlings, you have been wanting. And plant the seeds and seedlings according to the directions you researched.
The beautiful thing about pots is that their orientation to the sun can be changed easily.