How to build a green roofed garden store

Since I laid out my slate patio a few years back I’ve used it less than expected. I realised lack of storage was one reason for this. Along with the inevitable broken flower pots and recycling bins, the odd bag of rubble or scrap of wood temporarily parked until the next recycling centre trip was giving my back garden a builder’s yard vibe!

Instead of storing my rubbish in an ugly plastic box, I built my own green roofed garden store. I chose Sedum turf instead of wildflower because although both encourage pollinating insects, as Sedums are semi-evergreen they give you something to look at through the winter as well as summer.

The slide show briefly describes the stage by stage construction.
[tribulant_slideshow gallery_id=1 layout=”fixed” width=”600″]

Overall I spent around £200 on wood, fixings and the roof materials. Here is a more detailed costing.

Decking boards 115mm x 22mm, 6 pieces – £13.50 (on offer at Wickes)
Fence posts 75mm x 75mm – £18
OSB2 sheet, 11mm thick – £21 (cut to size at B&Q)
Shiplap boards 115mm x 15mm, 7 pieces – £59 (Robbins timber yard, Bristol)
Hinges + screws etc – £15 (low, as I already had several types of outdoor screws)
Sedum roof materials – £86 (for 2sqM)

The turf roof itself consists of three elements: a drainage layer; a crushed brick base; then the Sedum turf. All from

I saved haulage costs by collecting from their farm just outside Salisbury. I found them very helpful and they seem to be happy to deal with people doing small projects like mine. They also have an option for sedum in trays which has half the weight of turf, although it costs a bit more. Weight is a consideration especially if for example you’re green-roofing a shed, which is unlikely to be designed to bear that sort of weight.

As you’ll see from the slide show, the roof needs to slope and drain. However Sedum shouldn’t be allowed to dry out completely in hot summers. For watering consider it as somewhere between lawn and a potted plant. It also would benefit from some feed pellets in the spring, and maybe a trim if some individual plants get more woody, or weeds take root. Other than that Sedum is low maintenance.