I'm hoping to start a vegetable garden on my flat rubber roof this year. Probably tomatoes, bell peppers, and similar plants? My plan was to use 5-gallon buckets from Home Depot as containers.
The main thing holding me back is the weight. I did a test and a 5-gallon bucket with potting soil saturated with water weighs about 37 lbs. With a margin for error (13 lbs) plus another 10 lbs for the eventual weight of a mature tomato or pepper plant (optimistic, I know!). That puts each bucket at around 50-60 lbs.
My roof is part of a 3-unit condo, and I'm on the top floor with direct access. I and 2-3 other people have been on the roof without any noticeable issues. I also see that one of my neighbors has an AC unit on their side of the roof, and it looks like it's sitting on a wooden platform, possibly to distribute the weight.
If I aim for 12-24 buckets, that's a total estimated weight of 600 to 1440 pounds.
Is this amount of weight (50-60 lbs per bucket, which is roughly per square foot if the buckets are placed side-by-side) generally acceptable for a flat roof if spread with 2sqft / bucket? Would this be considered part of the roof's dead load?
Does anyone have experience with this or any insights into whether this is a safe idea? Any suggestions on how to approach this or if there are ways to mitigate the weight concern (like using specific placements, platforms, etc.) would be hugely appreciated!
Thanks in advance!
The attic underneath the flat rubber roof
Video for the attic: https://imgur.com/a/yAR5B5U
by dreamrecursion
1 Comment
Putting the buckets directly on the roof could be done if you are certain to put them on top of the joist, but that’s probably not easy to do. The easiest solution to weight distribution issues would be to place pallets on the roof to help distribute the load. Sheets of plywood would be even better.