Sure JD. I'll explain my greenhouse. I bought it as a kit from Sam's club. I wanted the one at Costco's web site but it was 200 bucks more than Sam's. It was $499 at Sam's club online. When I got it, I let it sit outside for about a month before I started building it. Why? Well I realized the base was just as important as the GH itself. So, I had second thoughts about it.
One day, I opened the boxes and spent the entire day reading and thinking of ways for designing the base. I went to a website online and got step by step instructions for building the base. I have a large flat area behind my house adjacent to my deck and pool, so I chose this site for my GH. The site wasn't totally flat. it tapered downward away from my house about 30 degrees. So, I rented a sod cutter and cleared the area and rolled away the sod. Next I dug a trench according to the GH base frame. You have to build the base frame first in order to build the foundation properly.
The hardest and most time consuming part was clearing the site and building the foundation. I used 4 x 4 pressure treated lumber. But I have to tell you, you have to put a protection barrier between the lumber and the GH base frame because the GH frame is made of aluminum and the chemicals in the lumber will erode the aluminum GH. So, I used 10mil gray tarp that I stapled around the GH, then I screwed the base to the 4x4s. I secured the whole base with 3/8” 2 foot long rebar and large U shaped nails. I placed the rebar 2 feet all around the GH.
Next I finished the frame and started working on inserting the panels. Once the frame is up, the panels only takes about an hour to slide in. The panels are held in place using plastic “s” clamps that slide on. Some folks had problems with these saying a good strong wind blew their panels out. I had this happened to one of my panels but it was my fault because I knew the panels were not secure when I installed them on that one panel and did nothing to fix it. One day, we got a huge down burst of wind from a semi-tornado 3 months ago. That burst of wind should have blown over my GH but I secured it well in the ground. But that down burst did completely snap off my bolted on pop up vent from my GH and blew out that one loose panel. It also picked up my huge 5 burner BBQ grill and threw it across my deck along with 2 large flower pots! I spent 2 months trying to clean out that pool! But my GH remain standing minus the ripped off vent. The moral of the story is make sure the GH is secure in the ground.
My greenhouse gets very hot in the summer usually 10 degrees warmer than outside temps in summer and winter. Last winter temps outside got down to 15 degrees. It was my goal to not let my GH get below 25 degrees. So I placed a small oil filled heater inside that came on if temps got too cold and it worked! I kept all my trees inside my GH except for about 10 trees. I kept them in my insulated garage which did get down to 25 degrees.
I finished my GH with 2 sheets of weed guard and filling it in with gravel and 12 x 12 pavers and sand. To finish off the GH I placed 2 inches of gravel all around it. I spent a total of $1000 bucks on it. It’s only 6 by 8 but it can hold a lot of trees. If I had to do it over again, I would build it bigger.