I can give you some help, although it's been so many years since I built mine, some of the small details aren't clear to me anymore. I'm looking at the newest version of the Harbor Freight manual, and the part 81 white plastic bushings are mentioned on page 17, in step number 5. Apparently the bushings were to be inserted over the part 78 Double Brace Bolts (part 78), before you used those bolts to finally attach the side diagonal struts (part 80.) Maybe you can locate the side diagonal struts on your greenhouse (part 80) and look at the bolts holding it in place, to see if it really matters if there's a bushing to space something a bit apart, on the long bolt part 78 bolt. I'm not sure how difficult it would be to back track, at this point, and maybe it's not all that important.

I'm not sure that that is the best design because: 1) small holes will not let in very much air, and 2) most adhesives I'm familiar with would not keep foam adhered to plastic film for very long, especially if the plastic had any movement in it. If it were me, I'd: 1) have a vent that lets in lots of air (you'll need it on a hot day), and I'd use a different design. One option is to simply cut a 10 X 12 opening in the sidewall, cut a somewhat bigger piece of plastic to cover the opening on the inside, and then fix the flap in place at the top edge with a piece of duct tape. You could add a little bit of weight to the bottom edge of the flap by stapling a strip of wood to it. If you wanted something fancier, you could cut out the opening entirely and frame it with 8 strips of wood to match the opening (4 inside and 4 outside). You would pre-drill holes so you could screw the pieces together, trapping the plastic between. Then you could close off the opening with another piece of plastic film stapled to the top of the inside frame. Or you could place a piece of foam in the opening to close it off (which would require you to make the outside frame a little smaller so the foam piece wouldn't fall through) Obviously there are many variations on this. I am just suggesting that some kind of mechanical solution will last longer than trying to glue foam to plastic.

Hi All, Thanks for your response. Cactusfreak - where did you purchase your pool cover? I have been planning on getting one of those eventually. When I bought the greenhouse I thought it was much more insulated and a lot of people (including the distributor), told me it would be more than warm enough with two oil radiators. It sounded like I would need more heat than that, but I thought it would work out. I think what I will do for this winter is insulate the greenhouse like crazy, get a good heating system and hope for the best. I'll have to look up Pittsburgh's weather records as well for the winter. If it doesn't work I'll just use it as a cold frame. I will be growing a bunch of orchids in the greenhouse and a handful of 'annuals' including Fushia, hibiscus, mandavilla and more. Some of the orchids are probably the most sensitive to the cold.

When siting mine, I went with a balance between close proximity, access to utilities and sun. I put it less than 50 feet from the house. That way, one roll of hose and underground wiring was enough to reach. It's downhill from the house for easy draining of the water lines, and I was able to follow an old and abandoned outside kitchen drain line to lessen the trench-digging. The remaining 25 feet of trench was hand-cut through the clays and outcrops of slate rocks to reach the gh. I buried two ordinary mid-quality garden hoses for both hot and cold water in the same trench, along with the electricity. I have that wired as an extension cord and it plugs into a GFI outlet located under the house. I usually leave the hot water side off and disconnected, but it's there if needed for some early spring gardening. I use it so seldom, if the cold hose fails, I can switch it over to the second hose and keep on a-going. I did not heat tape or protect the lines and they're only 6 inches or so deep. Draining before winter is a must, but you'd be surprised how cold it must be before they freeze. The hose has frozen several times with no apparent ill-effects. The water gets only warm to the touch on a hot summer day. I should add our well system has very low pressure, under 30 psi, which no doubt helps to minimize any damage from heat-related pressure builds. I've left these hoses buried year-round, this is our fourth season using them. They're so shallow that once they fail, all I have to do is pull them up, clean out the trench and replace. I plumbed in water shutoffs both under the house and outside of it for easy winterizing. The taps are right below our kitchen sink, so plumbing was a no-brainer. The electric panel is just one room over, so that job was also simple to do. As to your own specific problems, there's a few possible solutions I can suggest. If burial of the hose won't work, there are high-pressure-rated garden hoses. Keep the hose in shade, maybe mulch it, or cover it somehow. Remember to shut it off at the house and go back to the gh to relieve the pressure from the hose, saving it into a watering can so it's not wasted. If you're forgetful or it's a long trudge back to the shut-off at the house, put a timer on the spigot at the house that automatically shuts off the outside line after your usual garden quitting time and turns it on prior to your morning waterings. Some fancy timers have multiple on/off settings. There's also cheap clock timers that run for a preset period, say an hour or two, to let you do your chores then it shuts off afterwards. That's just one trip to the hose connection per watering session. Always fill a large watering can before finishing for the day so you have something handy for an emergency spot-watering. For a too-hot greenhouse, maybe several panels can be removed in the summer, even an entire wall or two and replaced with screening or just left open. That -will- help! A small utility pump, a large water barrel and a timer could provide a remote misting or even watering system. Rain gutters could be installed on the gh or house as well, collected in barrels and plumbed to where needed. No pressure, no worries of high water bills if a leak occurs. If there's no rain, just fill the barrels from the house spigot and use the same timed pumping system either way. For the ultimate in convenience, there's floating stock tank water shutoffs that work like your toilet. Get some rain, it fills the barrels. No rain, the house waterline fills it up. The pump and timer handle the watering either way. Another timer limits how much house water is used. You sit on the deck and watch for problems. There's all sorts of DIY plumbing answers for many of your watering problems. Just cruise the aisles and see what you can graft together. For planting, Ace Hardware has 5-gallon pails. Professional painters and drywallers get their stuff in the same thing. Restaurants get their pickles and condiments in buckets. Good luck! Once you're done, you'll always appreciate the automation! -Ed