I always wanted to do a building with a green roof so when I was approached by a local Steiner school for idea's on how to repair a pagoda with a leaking timber shingle roof I jumped at the chance to modify it to a dirt roof with plants growing on top of it.
The structure was originally built with the students as part of a class project back in and the actual framework was able to cope with a lot more loading than the roof was carrying with just the rotting shingles so adding tarps, ag pipe and topsoil wouldn't be a structural issue.
The first step after pruning back vines which had grown through the roof was to tarp the structure.
The tarps used were actually helicopter landing tarps from the Vietnam War.
Kicking footholes through the rotten shingles as we went up the roof with tarps in hand seemed the safest and easiest way to do the job.
The bottom layer of ag pipe was secured to treated pine battens left over from another job and the successive lengths of ag pipe spiraling upwards to the apex of the structure were secured with bugle head screws drilled from below through the existing battens.
After some fancy footwork laying the Geo fab landscaping bidum cloth it was time to cover one complete section or spiral with the 3.5 tonne of topsoil.
After many many MANY buckets the job was done!
All that was left to do was to plant some succulents and stand back to admire the transformation.
A few final buckets of top soil did the job of covering most of the exposed geo fabric, the rain will drain well through the ag pipe and the tarp will keep it all waterproof!