Sedum roofs are easy to plant, look great, stay green all year round and provide all kinds of benefits for wildlife and the environment.
What you need:
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Pond or butyl liner
- Plastic cellular layers or lightweight aggregate
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Fleece for filter sheet
- Soil mixed with perlite
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Seeds or plug plants
- Hammer and nails
How you do it: six simple steps
1. First ensure that the exisiting waterproofing on your roof does not leak and that the structure you are planting onto is sound and can take the load.
2. Next fix a layer of pond or butyl lining over your exisiting roof, nailing it along the edge. This acts as a root barrier and prevents potential leaks. For best results lay your liner in one continuous sheet, or overlap multiple sheets by 20cm.
3. Now add the drainage layer. You can use lightweight aggregates or performed plastic cellular layers which help to retain moisture while allowing excess water to drain away.
4. Next lay the fleece sheet on top which will act as a filter and stop drainage layer becoming clogged up.
5. Finally add the top layer between which should be made up of soil and substrates, such as perlite, to a depth of between 1-5cm. This layer should be lightweight and free-draining.
6. Now sow your seeds or plant plugs directly into the substrate top layer and watch them grow!
Maintenance
Sedum roofs are low maintenance and only require to be weeded once or twice a year.
For easier option, use pre-grown sedum blankets instead of seeds or plug plants. These can be rolled out on to the roof or grown medium.
! For your first project, it's a good idea to start small scale. You must ensure that your structure can take the weight of the soil and plants. If you have any doubts consult an expert.
