Going green on top
Sedum planted in trays in May last year (inset) and translanted onto the Firies roof this May
I RECEIVED a letter recently from a lady who has gone for a natural look on the roof of her house. From all accounts it is a simple technology that could have wider application in Kerry for more efficient and environmentally friendly housing.
She and her family planted sedum in trays, which they later transplanted onto the lean-to roof beside their cottage in Firies. The lean-to roof is made of corrugated iron. They nailed timber around the edge, put a weed mat on top, then added gravel and oyster shells they collected from Cromane and then planted the sedum. To date it all seems to be working very well. They also placed a bird nesting box up on the gable of their home and the sedum roof seems to have attracted birdlife. The bird box has been up on the gable for two years and only since planting the sedum, have a family of blue tits started nesting in it. They have also noticed a pair of wagtails and their young eating insects from the sedum plants in the trays.
Aside from attracting wildlife, sedum roofs decrease rainwater run-off during heavy rains â?“ as sedum absorbs lots of water â?“ and increase energy efficiency. Sedums are hardy, drought-tolerant, have non-woody roots and require little maintenance. They are self-sustaining and look good throughout most of the year. Many types of sedum are native to Kerry and can be found on stones and rocks.
Simple sedum roofs can be used on existing garages and sheds whether they are roofed with corrugated iron or an asphalt/bitumen felt layer. A containment frame should be constructed around the perimeter of the roof to hold the green roof materials. If the shed/garage already has an asphalt or bitumen felt layer, an additional layer of waterproof material is needed and you can use a single sheet of heavyduty pond liner (it is essential that roots and water cannot find a way through). It is a good idea to cover this layer with an old carpet to help support the material above. The non-organic material (80%) can be a mix of crushed brick, expanded clay, shells, gravel, shale etc. When planting the sedum onto the roof, plant them into plugs of good organic compost, but not peat.
For further information look up: www.livingroofs.org.uk, www.greenroofs.com, www.english-nature.org.uk
