You've done a beautiful job but I'm wondering if the roofing will support the snow and ice we sometimes get. Something to think about.

Thanks Rosies! I've never built a structure before that one can walk inside of, so I have spent a LOT of time building this so far; particularly with the digging and measuring.

The wind on Veteran's Day evening pulled off one of those panels from the roof (it was only held down with a couple screws). I may have to brace those pieces across the center if the weight becomes an issue. I also have to figure out venting options. How well do those pneumatic automatic vent lifters work? Should I hinge one of the cross-pattern windows on the roof and use one those lifts? I think that will be the least expensive option. Not sure how to deal with the plastic panel that overlaps the top edge of the window though. I will need rain to run off of it, but I don't want it going into the GH if the lift props the window open. DO you have any ideas?

I still need to figure out how to use a shower door for the door and enclose the triangle portions that make the apex of the roof.

It's nice it's finally looking like a GH. It is supposed to warm up this weekend, so I am looking forward to getting it closer to finished.

You need to turn your 2x4's on the top on edge. Laying flat they will bow even without weight. I don't mean to be critical just trying to save you some headaches in the future.

Your aesthetics are very well done. Your greenhouse is certainly no eyesore.

I have to second the concern about the old window as a roof, though. They are not meant to hold a load, and when they break, it's messy and dangerous. Plus, if rain water pools up, it will cause problems.

Poly carb panels are ideal for your roof, but I know they are expensive. I'm seeing $1.79/sq ft as I look right now.

Alternatively, you could fashion sheets of plywood as shutters for the winter to go over the windows. Then in the summer, they could be your shade. Without shade, a greenhouse is a pretty miserable place in the hot summer months. You will also want as many working windows as you can get for when it gets too hot.

Oh good point on the 2x4s at the top. Do the ones that go down the roof also need turned? Now is the time to fix these things! What I was going to do on the side ones was screw a 2X6 across that gap where the windows are just below. Would that brace that 2X4 you are talking about on each side? Here's what I am talking about:
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Also good idea on the panel. You are right about the not cheap! I was looking at corrugated ones at Lowes. Oye! That's why these plastic panels I found were exciting (free)! The old windows you see are made of metal in the crosses and frame. It's stronger than if it were made of wood. Maybe I could fashion a sheet of plexiglass over it?

I think the 2X6 would work in that area but the ones on the very top that the roof (no matter what is used for the roof) lays on has to be turned or they will bow and sag. The way they are now you're only getting 1 1/2" of support versus 3 1/2" turned up. Also the 2X4 across the top front that the windows are laying on has to be turned.
I really can't be any help on the vent. My old home made greenhouse (16 years old) never had one. It's made from the corrugated panels but it never looked as good as yours. We're thinking about building a new one next spring that's what brought me to this forum.
Even though the windows on top have metal frames they aren't going to work for the top. They will only be as strong as the glass which isn't going to be enough for snow and ice and laying flat hail would probably break them too.
I'm not a builder (I've only built a dog house and a lean too for a lawnmower) but I've been around a lot of building and helped my husband on a few projects.
Unless you already have the shower door I'd suggest using a storm door instead. As for the triangle I don't know what to suggest.
I know what you mean about cost. That will be the determining factor on weather we build a new one or not.
Please keep posting pictures because I'm sure it will be beautiful when you're finished.

A guy at work had the idea to make the two vertical supports on each side (the triangle part) and on the top of those put a 2x6 up edgewise across to the other side to give the plastic panels strength under them. I could do that, but the wood in the front you mention definitely needs to be turned. I think I have some plexiglass that can basically shield those windows. I like their look, but I think you are right about the protection. The snow has been 'weak sauce' as far as accumulation for YEARS in Central Kentucky, but life likes to spite me, so if I don't reinforce these windows you know 2ft will dump on the GH this winter! LOL

Thanks for your conversation. I am sort of adhoc'ing construction of this GH from rough ideas in my head. I'm enjoying the project. It's ike Legos for adults. :)

I took your advice and totally rebuilt the roof so all wood is on-edge. I spent at least 10 hours (through 2:30am Sunday) working on that and making the placement of the windows consistent, so they are all turned facing the same way per side, I spent the most time with that roof. I decided I am going to use those windows and put plexiglass over them, Though it was raining hard this last morning and the roof seems to be doing well. The plexi will make it smooth all the way across and rain will run off nicer I think. Just a few places to screw down or add silicone. I also need to do a gutter. The roof is very functional and strong including the window part at the bottom. I cut an exact fit of the window frame into the 2x4 and added strength by putting full 2x4s next to them on each side. The reason I worked so late was that there is a big storm over the midwest and wanted to build it as strong as possible before it hit. Plus it was warm and I hate working in the cold. I am nearing the end of construction. I need to buy a little more wood to finish up the one long side and then figure out a door and vent solution, I am thinking of hinging all 3 windows on that long side at the top, so in the summer I can just prop open that entire side. If I can put in a vent that opens and closes on the vertical above the doorway I think it will be the ideal spot. If I have to cut the plastic sheeting in the triangle areas under the roof I will put them there. I am not in any danger of being "too hot" this time of year, so I have time to figure out options.

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This post was edited by bencjedi on Sun, Nov 17, 13 at 22:19

Its a little smaller than what I have in mind for my future GH, but I like what I'm seeing, especially given that you're working with wood for most of the construction. That's going to be what I will use with mine if I ever get around to it.

bigmrg74 Yeah I have a small yard (house and yard sit on only 0.09 acre - not even a tenth of an acre). I am building it on really the only place it can go so as to have available sunlight.It's about the maximum dimensions I felt comfortable using, as I had to give up part of my gardening space. This is much larger than the tent greenhouse I had on the deck that it is replacing, so definitely a huge step up for me. I never imagined constructing something like this all by myself. I'm enjoying working with the wood very much.

Since my GH is on a raised platform with spaced board I put down carpet underlayment from when I ripped up carpeting in my house.
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I then put a waterproof canvas over it (from neighbor's discarded screen house thing):
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I also been working on the door\louvre vent. Will have to get some pics of that.. I just received the automatic opener for the vent and hope to install it this weekend. I actually moved the door to the outside instead of inside because of the flooring material. I need a good way to latch it closed outside (rotating stick would work) and a way to close it when I am inside (no handle) and have it stay closed.

Ben. I give you an 'A' for effort and trying something that most won't. A greenhouse is probably the most demanding of all structures to build well if one has any hope of longevity of the building.

You are using the windows as structural elements in the vertical walls. I know you said they are metal, but they are not designed to support load. That is the job of the framing. Vertical pressure, as in snow load, or even the weight of the roof itself, has the potential of cracking the windows. This will be exacerbated if any portion of the floor settles. All load stress will shift to focus on one spot and cause damage. I know it's late in the game for you to change this, but it's something to be aware of.

Beware of moisture building up under the "carpet" sandwich you have made. It will! Condensation will form because the earth/air are cool and the GH is warm. Rot will set in, yes, even in treated decking lumber. You're also going to be using a lot of water in the GH too. And if you add a hot tub, the walls are going to run pure water to the floor and sill plates will drench.

I don't mean to rain on your parade (GH), but I have done a lot of building... and over a period of seven decades, I too learned many things from the school of hard knocks. Enjoy the GH and learn from the experience.

The link is to construction of an attached GH, but the advice is really good, especially the diagram and notes on preventing water from collecting anywhere.

Here is a link that might be useful: Attached greenhouse

Ben. I give you an 'A' for effort and trying something that most won't. A greenhouse is probably the most demanding of all structures to build well if one has any hope of longevity of the building.

You are using the windows as structural elements in the vertical walls. I know you said they are metal, but they are not designed to support load. That is the job of the framing. Vertical pressure, as in snow load, or even the weight of the roof itself, has the potential of cracking the windows. This will be exacerbated if any portion of the floor settles. All load stress will shift to focus on one spot and cause damage. I know it's late in the game for you to change this, but it's something to be aware of.

Beware of moisture building up under the "carpet" sandwich you have made. It will! Condensation will form because the earth/air are cool and the GH is warm. Rot will set in, yes, even in treated decking lumber. You're also going to be using a lot of water in the GH too. And if you add a hot tub, the walls are going to run pure water to the floor and sill plates will drench.

I don't mean to rain on your parade (GH), but I have done a lot of building... and over a period of seven decades, I too learned many things from the school of hard knocks. Enjoy the GH and learn from the experience.

The link is to construction of an attached GH, but the advice is really good, especially the diagram and notes on preventing water from collecting anywhere.

Here is a link that might be useful: Attached greenhouse

Thanks for your wisdom. I just want to clarify a few things.

The windows are sandwiched between 2X4s on the top and bottom of each row which are supported all around by 6x6 posts in the 4 corners. They basically 'sit' on the 2x4's. The roof is anchored to the four 6x6 posts, so any weight on the roof should direct to the posts primarily and if there is some load on the low side, there's a 4x4 post horizontally at the bottom of that roof also which is also anchored to the 6x6 posts. If the posts sink unevenly I can see that might crack some windows, but hopefully the 4x4 takes the brunt of that weight to the 6x6 posts evenly over time and any sinking happens in unison. The floor has nothing to do with it.. which leads me into the next point...

The decking (floor) is totally independent from the walls of windows and roof. The deck is on it's own concreted 6x6 supports. This way if the deck sinks, it has no bearing on the rest of the structure. Think of the deck as it's own island inside a shell that surrounds it. If the deck sinks and the shell doesn't that's ok. If the shell sinks and the deck sinks that's ok too. If they both sink that's also ok. It's only an issue if the shell doesn't sink evenly all around where I might have window trouble. Time will tell on this.

We will see how the floor holds up. I did the same thing with no waterproof canvas over it in the old greenhouse (tent one). It lasted 2 years before the floor got funky and that was with no waterproof cover. Basically am experimenting here. I had the underlayment from ripping up carpet in the house. a free insulator, so figured I'd give it another try, but with the canvas over it to see what that's like. :)

I do appreciate your expertise, but you may not have been aware of my design choices and my thought process behind them. Hope it makes sense and I get some good years out of the design. It will certainly be better than that plastic tent greenhouse that this is replacing (2 seasons).

A guy I work with mentioned putting tar paper on the bottom side of the deck. Good idea?