roofing

Etymology 1

roof + -ing (“material, collection”).

noun

1. Material used on the outside of a roof, such as shingles.
   As towns continue to grow, replanting vegetation has become a form of urban utopia and green roofs are spreading fast. Last year 1m square metres of plant-covered roofing was built in France, as much as in the US, and 10 times more than in Germany, the pioneer in this field. 2013-05-10, Audrey Garric, “Urban canopies let nature bloom”, in The Guardian Weekly, volume 188, number 22, page 30
2. The process of constructing a roof or roofs.
3. A way of travel which consists in clambering over the roofs of skyscrapers.

Etymology 2

verb

1. present participle and gerund of roof