Basalt Rope After building a few EcoShell Domes with the Basalt Roving we have realized we needed more. So working with Sudaglass we have come up with this Basalt Rope. It is easier to handle and is just right for the EcoShell Domes. The rope is equal to 3/4 of a 4 mm bar. It comes in 10 kilo (22 lbs) rolls. Two rolls will build a 6 meter (20 ft) diameter EcoShell. This is a great home or storage. Basalt Rope for use in the construction of EcoShell I domes. It is easy to handle and to ship and far easier to use than the roving.