Yes, I'm using the 6 mil poly that lasts 4-5 years. Since I am going to expand this one, I too used an old roll I had sitting around as an emergency to in case one of the other greenhouses lost their top in a wind storm, which in winter, many times comes the day before a freeze. I found that over time, using 2 x 6s around the perimeter where I am tacking the plastic holds up way better and take the pressure better for pulling the plastic tight. You could do that one you have with 12 foot boards and make a 12 x 36 real easy. I built my first greenhouse with wood in 1988 and it still stands today, so using pressure treated wood lasts a real long time. Even those profesional hoop house kits are only guaranteed for 15 years and they are the twice the price. And if they get damaged, it is real expensive because they never fit back together without a big cost. On these, you may have to change out a couple of boards. About 10 years ago, we literally had 3 eyes of 3 major hurricanes go right by me in the same month, and besides all the plastic getting ripped off, it only cost me $100 to fix the 3 greenhouses I had at that time. Tom
