Old Window Greenhouse

[Jstpssng]

You can get some nice kits, depending on budget. The polycarbonate somebody suggested above better than glass in a lot of ways. It insulates better and is easy to work with. There's a reason why you don't see commercial greenhouses using glass anymore.

Having said that I have (6) 4x6 foot glass panels from old storefront windows I plan to use for a greenhouse. They are heavier than window glass, and they were free.

 

[walhondingMF]

The free part is a big deal. So far, all the window are free and I bought most of the corrugated clear roofing on sale already. Lumber prices are not as bad as they were either.
It will be 10x12 and I do plan on making the overhangs for the roof more than a foot. Probably go 24" on center for the rafters but use 2x6. Have not decided yet how many windows I want to put on hinges for ventilation. I have even considered putting the roof on hinges since it will just be shed style. Maybe 8' tall on front and 6'6" on the back side.
She did want the windows all spaced out randomly but I think I have her talked out of that. Just a pain to frame that in an then finish it our nice.

 

[Oaktree]

The free part is a big deal. So far, all the window are free and I bought most of the corrugated clear roofing on sale already. Lumber prices are not as bad as they were either.

Following this thread with some interest since I'm thinking of building a small greenhouse without breaking the bank. Lotsa good ideas here.
How does that clear corrugated roofing stand up? I ask because a neighbor used some on a porch roof...one hailstorm and it was full of holes...and the hail we get here in northern New England is pretty wimpy compared to what you midwesterners get. Also wondering about how it stands up to UV exposure or freeze/thaw cycles.

 

[MAX-24-Dean]

Pictures please!

 

[jaxs]

Following this thread with some interest since I'm thinking of building a small greenhouse without breaking the bank. Lotsa good ideas here.
How does that clear corrugated roofing stand up? I ask because a neighbor used some on a porch roof...one hailstorm and it was full of holes...and the hail we get here in northern New England is pretty wimpy compared to what you midwesterners get. Also wondering about how it stands up to UV exposure or freeze/thaw cycles.

Since you name issues that concern you we can address those and after we know exactly what op's are, we can address his challenges. I have never used transparent roofing because (A) As you point out even moderate hail will destroy most conventional transparent material. (B) It's unnecessary for a small greenhouse. During months greenhouses are in use the sun is in Southern sky with sufficient light entering vertical transparent walls. As location move's North angle of sunlight entering window changes so to lay out footprint,temporarly set a 2x4 horizontally at 8' from ground to see where shadow falls on ground. That tells you how deep the house can be. We will use 10 feet. If anything blocks morning or afternoon sun adjust orientation of South wall to maximize sun exposure at apposite horizon. 10 deep x 8 feet wide x 8 feet tall South wall should be enough space for all but serious growers. Transparent material isn't necessary in East and/or West wall but 1 or 2 feet is enough to realize 90% of what entire wall would increase available light. You can reach to tend shelves from floor to 6' on South wall and 2' tall shelves on Nort wall will receive full sun or taller shelves mid way receive a good amount. Metal or composition roof with a little overhang will offer protection for transparent material. Despite name of structure,do not use green transparent panels,they won't work.

 

[walhondingMF]

I also have an app called the Sunapp. Its free and gives you year-round sun locations and times.

 

[yomax4]

I built a lean-to type of greenhouse off of a shed. I used reclaimed patio slider thermal pane door panels. They were free and will hold a snow load in the winter.

 

[tomplum]

We did a solar greenhouse at the last place. It had 10 patio door glasses @ 60 degrees on the face of it. I built that frame out of scrap 3" channel in kind of an A frame from the side view. Had garden beds inside, even did aquaponics. Trimmed the outside of the glass so it looked nice. Some of the glass had gotten cloudy as time went on. Still worked well. Polycarb can be expensive, but can also make things a lot simpler.

 

[buckeyefarmer]

I got 8+ old doublehung windows with external storm window if anyone wants them.

 

[walhondingMF]

The foundation is almost complete. Just have to glue the last sill boards down. I had to wait on a "go" from the wife on the door location. I also have a start on the front wall, which will be the tallest and have the door in it. My plan is to build the front and back walls first and stand them up. Then, build the roof on. I'm not going to permanently screw the windows in until the entire structure is up and painted. The wife is going to have to scrap and paint all of them before they go in anyway. I am also going to prime all of the boards with Kilz before I even screw them together and do the finish painting while its standing. I will start taking progress pictures and posting.

 

[tractorbynet11]

Anyone built a greenhouse out of old windows? Starting a project and looking for advice.

I built one 15 years ago. Had old windows from a house I tore down, had some 2x4's, had screws, and a screwgun, and at that time, had some energy, so.... boom. 2 days= free greenhouse. Still standing. The intense heat dried up the old window glazing putty, and a couple of wdows rattled loose in the wind, but didn't break. I siliconed them back in. Some of the mullions are rotting, but still hold. If I did it again, I would pound some clear 100% silicone over all the putty making sure the bead makes contact with the glass on one side and the wood frame on the other, and I'd be more diligent about repainting the frames every 5 years. That way it would last a long time. But hey, 15 years for a free greenhouse (10x10) is not so bad either. and it's still going.

 

[tractorbynet11]

I got 8+ old doublehung windows with external storm window if anyone wants them.

Someone take him up on that, those are perfect for a greenhouse.

 

[walhondingMF]

Anyone see any good reason why I could not use 2x4s as my rafters? Probably going to go 24" on center but cut 2' 2x4 "stringer" to run between them every 2 feet. They will be running across a 10" span. I can use 2x6s but I want to keep it a little cheaper and I just don't want the roof to be that heavy. I am considering putting the entire roof on hinges so I can lifting the back end up for ventilation towards the end of the spring. I feel like 2x4s with cross supports should be plenty strong to hold up the plastic roofing.

 

[MossRoad]

Snow load
Wind load

Those would be my main concerns

 

[tomplum]

I'd say that a 2x6 is a better solution for a leak proof roof, let alone if you get snow. We don't get much snow by me, well just got 10" but.... So I've done well with 2x6 rafters on my leanto and loafing shed. On the last one, thought I'd notch them for the 2x4 purlins. Both hold up 12' steel. Takes the worry out for when these wind and snow events happen.

 

[walhondingMF]

You know, notching them isn't a bad idea. I may go with 2x6s after all. Still need to look at what roofing I already bought and see what else I need before I make any purchasing decisions for the roof yet.

Another question... The clear corrugated roofing has foam pieces that fill the ends where the ridges are. I know I want to keep in as much heat as possible but might it be a good idea to leave these out? Its not a lot of air, but maybe enough to let the greenhouse "breath?"

 

[jaxs]

I feel like your original idea of opening roof or otherwise controlling when and how much structure breathes would be best.

 

[Yander]

Anyone see any good reason why I could not use 2x4s as my rafters? Probably going to go 24" on center but cut 2' 2x4 "stringer" to run between them every 2 feet. They will be running across a 10" span. I can use 2x6s but I want to keep it a little cheaper and I just don't want the roof to be that heavy. I am considering putting the entire roof on hinges so I can lifting the back end up for ventilation towards the end of the spring. I feel like 2x4s with cross supports should be plenty strong to hold up the plastic roofing.

Use 2×4 but do not go 24" on center especially if you live where you get heavy snow.

You're not using plywood sheeting that polycarbonate isn't very strong and I think you're better off using the smaller wood but closer on center like 16 in on center. This is assuming you're using a gable roof and not trying to span the whole 10 ft with 2x4s. Just my opinion.

 

[walhondingMF]

I am going 10' with a shed roof. Maybe I will just go with 2x6 and figure out a good way of lifting it. If I have to use a jack of some kind I will. I am leaning towards notching them now with the 2x4s laying flush. Makes more surface area for the plastic to lay on. I can't imagine the price difference being to great between 12' 2x4s and 2x6s.

 

[tomplum]

Greenhouses are such an individual thing. Seed starters VS a constant use GH, what you grow, when you want to grow it, where you are make it -a living breathing thing really. Ventilation always seems necessary and it is good to be able to vary the amount due to heat and humidity. Shade cloths on the windows should be at least thought of to keep temps down. A fun journey and good thing is you don't have to create the perfect thing all at once. We did roof top poly vents. Built a frame, curbed it so it wouldn't leak. Added the little automatic vent openers. In the end, something else simple we did made all that unnecessary. Have fun.