Sedum Mats

Sedums have been used alot for planting on green roofs because they are resistant to wind, frost and drought. Sedums absorb water really well. Some companies, such as living roofs, http://www.livingroofs.org/ , supply pre-made sedum blankets that are rolled up and can be transported to the buyer of the green roof and simply installed by unrolling. The depth of the growth medium is 2 cm. The growth medium is laid on a base layer of Polyester, Hessian, orporous polythene. When the growing roof is installed it is placed on 5-7cm of growth medium. Probaby all the usual layers for the green roof are already installed (eg. drainage, waterproofing etc) I have not read information yet regarding tests of the amount of reduction in heat transfer through these roofs. If anyone has such information I would love to read it.
Dr Rita Carson and Heat Team A