Then it’s “strap”, check it’s level and start filling the tank with the garden hose to help weight the tank down. We gave the tank a thorough clean on the inside to make sure we were starting with a clean tank in view of the warning about organic matter “blooming” with fertilizer from the sedum roof.
The concrete lorry arrives late in the day after a few beefy showers. We had taken the precaution of temporarily connecting the outflow from the the roof to the tank to avoid any of the side of the hole being washed onto the slab. We had some considerable flow into the tank during the rain, as the sedum had already had a good soaking over the weekend, so it’s a good job we did hook it up, and pleasing to see that we will get water in the tank! Phew!