
When it comes to rooftop landscaping, smart roof buildups are the key to a successful and long-lasting design. Whether you’re creating a podium garden or an elevated terrace, managing drainage effectively is critical.
At ground level, things are simple. Raised Planter Edging is designed to retain soil while allowing water to drain naturally into the ground. Using systems like Anco or Velox Rapid Edge works well here—especially if the planter base is set below the finished floor level (FFL). In these cases, a filter fleece is optional but recommended.
However, above-ground installations present unique challenges. When planters sit on surfaces like paving or tarmac, natural drainage is no longer available. Therefore, the surface must be flat and stable. Velox Rapid Edge is suitable in this context, but before proceeding, it’s essential to check three things: is the surface level, how will drainage occur, and is the planter base edge visually acceptable to the client?
Now let’s explore roof buildup systems, especially where planting is introduced above structural slabs. Unlike ground-level projects, podiums and terraces rely on engineered drainage solutions. Three common build-ups are:
Blue Roof Systems – Built for water storage, these are strong, level, and planter-ready. Add a filter fleece, and you’re set.
Insulated Roofs – Require a drainage layer, as placing planters directly on the insulation will not allow for effective drainage.
RC Slabs with Membranes – Also need drainage voids to function properly.
In these more complex setups, Roofcell by Geosynthetics offers a great solution. Just 30mm thick, it creates effective drainage without overcomplicating the structure. Topped with a filter fleece, it keeps soil in place while water drains into the roof system below.
Every buildup needs the right drainage approach. Keep is simple, keep it smart and you’ll get a system that works and lasts.