Project: Sempervivum roof from recycled materials.

This short wall at the house entrance had the unfortunate habit of channeling water into the basement.

I collected recycled wood from the garage, mainly 2 X 6 's and some plywood, and constructed the box in this photo. The bottom slopes away from the house. The liner is recycled black rubber pond liner. I still need to construct a drain system so that any water that collects will be directed away from the house.
The box will be filled with coarse broken rocks and slate, perlite, and potting soil. Sempervivums and sedums will be planted as a living roof. These plants tolerate dry conditions, poor rocky soil, heat, and cold. I've been sticking starts between rocks in a recycled concrete wall, and they grow well there.

Sempervivum has a long tradition as a roofing plant. It is very durable. The name means "I always live" and refers to the plant's durability. They are originally from the Mediterranian and Himalayas. Romans grew it at their entrances to show their prosperity, and in Northwestern Europe, it was grown on roofs to deter lightning and fire.

Sempervivum is used today in projects for creating "green roofs" in urban settings and for home projects. It will be fun to see how this project turns out. My main concern is the northern exposure, but I already have a number of these plants in north facing locations and they seem to do fine.