Step 9: Install hut
A waterproof membrane was attached to plywood and then old fishing net was draped over the roof to provide the moss with a stable foundation.
The bridge has considerable spring to it - it has a few inches of travel just walking on it normally. Bouncing on it will flex it (the section that isn't supported in the center) about 8 or 9 inches.
Total project cost: just over $10,000 not including donations and a few hundred hours of volunteer labor.