If you run any sort of food-related business, you know that providing transportation and refrigeration for perishable goods like fruits, vegetables and herbs takes a good chunk of your food budget and isn't always so great for your carbon footprint score.
If you've thought about a rooftop garden to provide tomatoes, berries and fresh rosemary, you're not alone. Many facilities are transforming their roofs into instant sources of fresh ingredients.
Here are the steps to take to determine if this kind of roof will work:
1) Be ready to replace or re-seal the roof.
While not necessary, it helps to cut installation costs for a growing roof if you combine the upgrade with a new roofing job.
Your roofing contractor can tell you about the load the roof can handle, the type of covering recommended and the various growing systems available. In the rare case that a rooftop garden is not possible, they will let you know as they do a survey of your existing roof.
Some roofs need structural repairs, new flashing or new forms of drainage to handle the extra weight of a hydroponic or other planting system. Having all the work done together will lower overall costs.
2) Add up the cost of perishables you already purchase.
Determine which perishables you could grow, in what quantities, and add up how much growing your own will save you in supplier costs as compared to the energy needed to grow the produce yourself.
Do the math for a month, for a year, and for five years. Is it worth it to invest in a rooftop garden? That depends on your particular vegetable, fruit and herb needs.
Remember to factor in energy costs for any heating, fans or pumps. This rooftop project in Canada feeds 2,000 people a constant stream of fresh produce for $15 in fuel costs per day.
There are also labor costs to consider, as plants must be fed, pruned and harvested.
3) Determine the long-term cost of maintenance.
For many rooftop growing systems, there are few maintenance costs once the growing spots and irrigation lines are in place. While ingredient costs may increase, the price of seed and the price of nutrients are expected to remain negligible.
If you live in an area of average rainfall, water is provided for your garden by the clouds and will lower your building's storm runoff if properly diverted. This might offset the cost of running the garden if your sewage fees are reduced.
There will be some maintenance of equipment necessary. Periodic inspections of the roof should be conducted to ensure its integrity.
Your roofing professionals, like those at Lawson Brothers Construction, can help you determine if a rooftop garden will work in your location. You can always start out small with a few plants in an enclosed greenhouse-type space and see if the effort is worth the return. Your roofing specialists will help you get started safely, using the right materials for your facility.