sedum
Sedum installation completed!
Today we had a visit from Chris and Richard from Bauder who showed us how to lay our sedum roof covering, and gave us some handy installation tips for when we finish it tomorrow with our friends!
We began the process by rolling out the drainage mat (Bauder SDF mat) which has two laps, one on the top of a long edge and the other on the bottom. This mat is laid out in the opposite direction to the sedum blankets, and the overlaps are flattened out on top of the adjacent roll.
The pre-grown sedum vegetation blanket has a selvedge along one edge so to speak, and these laps are also designed to be laid under the matching edge of the adjacent blanket. First the exposed top edge must be cleaned from all vegetation, and then the two blankets are overlapped and the vegetation edges butted up to one another, resulting in a complete sedum covering! The joints are also staggered to prevent any continuous seams.
The SDF mat is extended 100mm beyond the edge of the sedum so that when the pebble perimeter is installed this helps to weight it down and keep the system in place. Another great tip from Richard and Chris was to use a batten along the edge of the sedum to clean off the vegetation layer at the edge and to lay the stones against, so that you end up with a really neat edge to the pebble border. There is a 300mm wide border to the whole roof perimeter, each rooflight, and a larger space where the solar thermal panels will go, so we are left with about 77m2 of sedum area in total.
It was all pretty straightforward once we had had our mini induction into sedum laying, so the next day our sedum laying team (the same fellow architect friends who had helped us previously with the Isoquick insulation) got to work, and here are the results!
These photos show the first few rows going down, making sure that the laps on the edges of the SDF mat are fully tucked under the vegetation blanket, and me finishing off one of the edges whilst the guys bring the pebbles for the perimeter up to roof level via the hoist.
The team taking a well deserved rest at the end of the day…
Giving the roof a good water at the end of the day…
The final result!