Solar Passive Greenhouse : Sitework checklist
Drainage, Insulation, Flashing |
Stone & Gravel |
- Sitework You aren't going to be providing water or electricity to your greenhouse - so that's moot.
Excavate down to clay, about 18", stockpiling topsoil for later. If you have clay soil, some drainage is a really good
idea. You'll be adding a very simple drainage system around the edge, and perimeter insulation.
- Assuming the site is not perfectly level, make the excavation at least 18" deep on the high side.
- The excavation size is the greenhouse footprint plus 2" on each side to allow for 2" of foam (pink) insulation.
- Smooth the bottom of the excavation with a slight slope (at least 1:10) downhill (the same
as the slope of the land) towards the lowest corner of the greenhouse.
- Stockpile any extra clayey soil - not on top of the top soil!
- At that lowest corner, add a drainage trench and I recommend doing it immediately so that the first
rain comes, your excavation won't be full of water for a month.
- Make the slope of the drainage ditch about 1:10, or if you do it as we did, in the rain, just keep digging until
- Around the perimeter, dig down about another ~8" deep x ~10" wide.
2 x 4 Walls