RAISED BED ON TOP OF MY WORKSHOP
paulkane1955 Posts: 3
Could someone kindly help me with some advise. I have 25 mtr square roof on my workshop,I would like to know is it possible to build a 8x4 feet raised bed , i intend to put glass on top of the raised bed,I would like to make it about 4 feet high,so as i dont have to bend down to much,What way would i have to fill my bed,ie,for draingage ,what materials to use,I need the full rundown on everything that i need to complete this project,my roof will take the weight that is involed in this project,all help is greatly appreciated.
Yours Kindly Paul
Also remember to factor in the weight when the soil/composts are saturated as it’s significantly higher.
East facing, top of a hill clay-loam, cultivated for centuries (7 years by me). Birmingham
It also depends what you want to grow in it. Are we talking raising seeds, growing annual vegetables and salads or permanent planting?
Apart from raising seedlings and young, tender plants, glass should not be necessary. If frost is predicted a horticultural fleece or plastic cloches would suffice and help keep the overall weight down.
Most veg need a depth of around 18” and the raised container would need to be sturdily constructed and lined with plastic (old compost bags stapled to the inside work well). You would need drainage holes drilled through the timber/plastic liner and possibly a drip tray below. This depth would be fine for most perennials and some dwarf shrubs too.
If you want a deep, solid construction, consider breaking the volume/weight up by splitting the desired planting area into four separate constructions, say four beds of 3x3’ or 4x2’ and placing them strategically over supporting roof joists, spaced out over the roof to spread the load. A series of smaller beds also have the advantage of being accessible from all sides, easier if you have difficulty bending and stretching.