1. Considering the total cost of construction and labor involved, the best quality wood is always cheaper in the end, and if you use a really good, penetrating oil stain on the wood before you use it, you will get multiple benefits: increased life, nicer apearance, and less labor, because it's a darned sight easier to stain lumber spread out on sawhorses, than trying to do it after the structure is completed.

2. You best bet for a door would be a good, insulated storm door that you can buy at any big box home center for about $200.00. But if you want to avoid a lot of extra cost, you might want to consider a standard sized door, and that means 36" max. Or, size your RO to fit a pair of the narrowest standard sized, which would be about 32" each. Custom sized doors are real budget busters.

However, a pair, even with extra reinforcement, still won't close as tightly as a single. We refitted the all aluminum door that came with my Cross Country GH with a solid wood core, vinyl wrapped storm door, which is not only more solid and insulating, it allowed us to install a pair of hydralic closers.

RE: roof vents: A GOOD carpenter can make anything, and simple awning style window farmes are pretty basic. If they don't know how to use a dado blade and a router to make one, they are no good at all.

3. Good contractors have CAD programs these days, to create working prints. You might also find independents that convert rough sketches to "blue" prints, but they would need to be qualified in construction. It's worth a try though. You never know, until you do.

Otherwise, is your design all that complicated? A 12 x 12 GH frame shouldn't be, and as long as you specify the basics, I can't believe any decent contractor couldn't build it.

Thank you, birdwidow. That was the most helpful reply I've received on any forum.

Hank

Here's another viewpoint for your door: If you're handy enough to build your gh from scratch, why not make the door too? That way, you can make it to your exact needs, and by using double or triple-wall polycarbonate, it will be insulated far better than a standard storm door.

Use 2x4s for the frame, and attach 1x2s on the inside edges for your door-stop. Construct the frame for the door out of 2x2s, and screw the panel to the outside. Apply weather-stripping to the edge of the 1x2s contacting the door frame, and line up your hinges. You'll have some choices with door handles, although you may want to go with a simpler arrangement with exterior latches rather than drilling and seating an interior latch with a knob.

Storm doors, in and of themselves, really don't insulate that well. Their main purpose is to create a dead space to trap air between the storm and the main door. This air can be a few degrees warmer than the outside, but to say that a storm door has a significant R-value would perhaps be going too far. Most storm doors have some sort of aluminum structure to them, and that conducts heat/cold like nobody's business.

Just my two cents...

Bruce C.

If you have a Habitat For Humanity "Restore" store (they sell building materials) you might be able to pick up a new or like new door for a good price. Newer patio sliders or glass doors that hinge and open with good glass lose much less heat than older ones.
PQ

Bruce: you are correct in your assessment of hollow aluminum storm doors, and why I went to vinyl wrapped solid wood. However, an aluminum skin over dense, rigid foam is another matter and was my preference, but time was short and the vinyl over wood in a size to fit my CC GH was available.

Nevertheless, it has performed well in our sub-zero temps, that I doubt Hank faces in Z-8, and the double hydralic closers assures that it's open no wider than necessary for me to slip in and out, and closes tightly behind me.

You are also correct about constructing a door; presuming one has the tools, space and skills to do it. Otherwise, it's a custom job and very, very pricey.

But in Zone 8, where Hank will be constructing his GH; does he really need anything more elaborate or expensive, than a good quality, insulated, stock storm door?

Hank: what item larger than a big wheelbarrow are you really planning to take into a 12 X 12? None? Then 3 ft. wide is plenty, and every increased inch of door width, means that much less of usable bench space.

Whatever your final decision: if you construct your GH around your desired use and interior floor plan, you will have what you need, to get what you want, and in the end; for a hobby GH; that's the most important consideration of all.

Good luck, and above all: have fun with it.

I live in Zone 8a, and we have occasional winter nighttime lows to 20F (potential for lower), and many in the 30s. I grow orchids, and need to maintain temps above 50F which unfortunately is not always possible given my current temporary setup. (I'm learning that my collection can handle cooler temperatures, but it's certainly not good for them!) Depending upon what one is trying to grow, and the minimum nighttime temps one is trying to maintain, a storm door might be fine. What also needs to be factored is the type of heating being considered. If BTUs are not an issue and there are plenty being generated, then one wouldn't need to be so concerned with the R-value of the door.

If Hank is building his own gh, he already has the tools, I would presume (saw, power drill), and constructing a door would be no more difficult than setting/leveling the foundation, etc. The most expensive part of building a door would be the polycarbonate piece fitted to the door frame -- maybe $50? The lumber, weatherstripping, hinges, and latch possibly another $25. I know from my own plans for a better gh that the additional cost for a storm door would be something I couldn't justify. Also, many of the orchids I grow require a lot of light, and a door which allows the maximum of light through would be important. I'll need to place my door on the east wall, so this is an issue for me, but maybe not for others.

I guess we don't know enough of the details of this project -- minimum temps, what he wants to grow, etc. -- to give better answers...

birdwidow:

I'm planning to have a dwarf orange tree in the HG during winter and move it outside when danger of freezing is passed. So, it's a trade-off between heavy pruning and a big door.

Hank -- if the main purpose of your gh is to winter-protect your orange tree, might it change the design (or need for it entirely) if you didn't have to move it? The reason I ask is because I grow citrus in the ground here. It's a little bit of trouble, but it can be done, especially if you only have one tree to worry about. As long as you keep your tree under eight feet, it's doable.

If you're interested, I can tell you how I do it.

Bruce

bcfromfl:

Thanks for your offer and your suggestions. I will move most of my orchid collection to the greenhouse; so, wintering a dwarf orange and maybe an avocado will just be extras.

Hank

Hank: Trees? Oh, sorry. That does make a difference.

You could buy unfinished, 5 - 6 ft. wood framed patio doors and stain them to match the rest of the GH frame. I've been writing on the presumption you are not a carpenter, because you asked about one making windows, and blueprints, and a contractor.

As skilled labor will be far your greatest expense, do cost out the difference between paying for custom, and buying stock items at Home Depot.

You might also be find that buying stock thermopane awning windows to use as vents, might also be less costly than having them custom made.

Check out the websites for some of the major door and window mfgs., such as Pella and Anderson. They should give good information of what's available.

Once you know what you need, and the model #'s, let your fingers do the driving for cost comparisons.

And- don't be afraid of using a combination of thermopane glass doors & awning windows and polycarb. it's done all the time, and you will have to dig deep to find a carpenter to construct any door or window to fit, seal and operate near as well as what is produced in a factory.

Hank, BW's initial advice regarding the doors is confirmed by the fact that many greenhouses come with a regular storm door, standard. Mine is a standard Pella storm door, straight out of the Pella box. Is the 36" width still too small for your tree?

Did you find any more information on the "warpability" of the kiln-dried treated lumber?

stressbaby,

I found that KDAT lumber is substantially better in warpability and all other respects than standard treated lumber; however, at my local building supplies places, it costs just about as much as western red cedar. I think, since I will seal rafters in any case, I could go either way.

Hank:

I appreciate your concern about warping, but in your area, termites may be a greater danger. If you choose straight, treated lumber, lay it out on a flat surface long enough to be sure it's completely dry, then really saturate it with a penetrating stain-sealer before using it, it's unlikely to warp.

Also, as dimensional lumber is always of a better grade then smaller stock; if you use 2 x 6's instead of 2 x 4's to frame, they will be far less likely to warp and the cost difference for such a small structure may be not be all that great.

It could be worth your time to crunch some numbers, just to see what you come up with in a total cost difference.

I guess I am wondering why you feel that it is necessary to use treated lumber for framing a greenhouse. There have been several discussions on this forum in the past about this, including how to finish ordinary lumber for use in high humidity environments. Treated has so many disadvantages that I would think aluminum would be preferrable if you want something that will resist the elements and have a long service life.

The problems with dripping treatment chemicals, difficulty in machining the lumber (I don't use my good table saw and dust collector because I don't want the treatement chemical laden sawdust to mix with the good sawdust I use for composting), the need for stainless or heavily galvanized hardware, etc. seems a lot of hassles considering the slim benefits.

Try using the search engine to find those other threads.