After a two week setback due to a nasty cold, I've pretty much finished the greenhouse. 2x4 pine framing covered in greenhouse plastic, which has the texture of visquene but has been specially treated to withstand damage from UV rays, so it lasts longer and is a lot more expensive.
I ran battens down the rafters and studs to hold the plastic in place to increase strength - it's snowing right now so it will have its first test tonight.
The clerestory (the vertical portion at the peak of the roof) will eventually have windows, but I have just tacked the plastic over it for now. The windows will allow me to adjust the temperature and ventilation.
I haven't quite figured out how to organize the inside, yet. A place for tools, a workbench, and shelving for the seedlings will all be needed. It's waterproofed now, and I have one thermometer inside and one out to monitor the difference in temperature. I may also run electrical and water (when I re-do the sprinkler system) for added convenience.
Matron's New Garden
1 day ago