So we just started building our second glass house. If you search under my user name you can find pics of the first one. We moved even before we got to finish that one so the new owner got a great perk with the house :) Got the foundation and floor in this weekend (now have to run down and get the building permit!) and am waiting on Home Depot for 2 16 foot beams I need for the top sides. This one will be 12 x 16 with 10 foot high walls and and an 8 foot ceiling peak. The first greenhouse was 8 x 12 with 8 foot walls and a ceiling height dictated by the windows I had. This new one will have a metal roof so we will have a much steeper pitch. I went to pick up some windows from a lady on Craigslist and she also threw in these 2 great old french doors - really narrow and tall. They will be the focal point of the building. Can't wait to get the walls up. It's like putting a puzzle together. Someone on my facebook page said:" You know you can build a pvc hoop and plastic greenhouse for about $250." I said it wasn't really going to be used as a greenhouse and I wanted something a lot nicer looking than that for my glass garden house. It has to fit in with my 1780 colonial.

The rock wall is a great idea! I hadn't thought of that! The plastic doesn't completely touch the ground on the back side and a rock wall (if I can fit it in there without crushing the asparagus on that side) would close the gap and be a neat way of helping store heat under the hoop cover. Thanks! To keep the temperature of the cold frames (AKA sun boxes) where I want it, I merely slide the glass on top like opening a window a crack or make it a wide opening. This allows the heat to escape. I don't have much going on in them yet. I did plant carrot, radish and spinach seeds this weekend in the shallow ones as an experiment. It is supposed to warm up into the high 60s\70s at the tail end of this week, so it will be interesting if I get some germination with that. I collected more pieces from that old trampoline. The curved portions that make up the giant ring.. as it turns out can also fit together into a U-shape also (albeit curvy), but they are taller, so with more plastic I think I could get away with another hoop house a little taller on the other side. Maybe the big Swiss Chard and garlic chives would like that?

Sandblasting is indeed a quick and effective means to remove rust and old paint to bare metal, but you must be careful not to overdo both the size and sharpness of the grit and air pressure. If you don't have a small air compressor with an adjustable pressure valve, this would be a good excuse to buy one and you will find endles uses for it after you are done with your GH project. The pro lined up those pieces to avoid wasting grit and yes, lining them up to allow you to sweep back and forth while getting a lot covered with each pass, while avoiding too much in any one spot as you would with spray paint is how to do it. Then, after you are done, or think you are, go back and catch any spots missed during the mass application. Sandblasting grit comes in many types and sizes, from pricey silicone beads used in auto body work, to plain sand, available at any garden center, but for your your application, just plain fine sand should be sufficient. However, it's important to use only CLEAN sand and for that, the kind sold in bags for children's sandboxes may be your best bet. To prevent wasting grit, go over the rusted parts with a steel brush to remove as much of the large or loose bits as you can before you start sandblasting, then blow it all off with air, so you can see the spots requiring the most blasting. Repeat compressed air only and a close look between each sandblasting application and you won't miss a single spot. BTW: If the GH walls are chambered polycarbonate and have any debris in them, an air compressor is the easiest and quickest tool for clearing them before they are resealed on the ends. Compressed air is also a great way to remove any dust that has drifted down and settled onto dry to the touch painted surfaces between coats. You can also make your finishing job a lot easier, faster and result in superior results by adding a paint gun to your compressor assessories and if you are able to spend a bit more and want to have those steel pieces look as good as possible, to hold up in weather and water as long as possible, bypass Rustoleum and use auto primer and paint, followed by clearcoat. For ease of application and lasting appearance, the latest in acrylic automotive paint really is superior to anything you will find in the paint dept. at a home center and unlike oil enamel, doesn't need baking to develop that rock hard surface; just the patience to give it time to completely cure from paint to clearcoat. How nice for you, to be able to paint the metal structure of your GH any color you want: Perhaps to match and/or compliment your home? Oh, yes: You didn't say how badly rusted any piece is, but after you clean off the last speck of rust, if you find metal that has been eaten away and want to fill it in, borrow another page from the auto body shops: Bondo, available at any auto store.

I've had some VERY extensive experience with plastic and I can tell you for sure that most of the above-mentioned concerns are nothing short of silly. First of all, heat mats will not weaken the plastic over time. Most plastic benches are heat injection molded, which means that heating will actually tend to strengthen the material. If you want to waste every season replacing rotting wooden planks and making vain attempts at decontaminating porous or rusty bench tops, go ahead. I'd rather spend my time and money finding ways to improve overall yield. Secondly, you can get plastic benches with plastic legs that seem to NEVER rot or crack. I know at least three people who have used the same plastic benches and legs for more than 15 years. The key is to buy the really heavy-duty ones, like you the ones you see as displays in the garden center at Wal-Mart. I was able to find the phone number for the manufacturer on one of the benches they have there. Try plastic before you scoff, you'll be thanking me in about three years.