pictures of a greenhouse I built this weekend

[Ignoramus2772]

The idea was to extend the growing season by a month in both spring and fall...

[chaz]

do you need directions to my place? :)

[Salty Thumb]

Ignoramus2772 wrote in news:ca3d5h$u1q $ [e-mail]:

I've left things made out of untreated pine outside. They turn grey after a year or so (SE Virginia). Structurally they are still sound (or at least appear to be), but now I usually paint wood if it's going to be exposed outdoors. Don't know if it's a good idea or not for a greenhouse (as far as plant toxicity and envirofriendliness).

Speaking of structural integrity, are you sure that baby is going to hold up? I'm not sure how comfortable I'd be with nothing under the rafters. Are the columns made of wood? It's kind of hard to tell, they sort of look like PVC pipe. Why not make the whole thing out of pipe? It's got to be easier to take down (if necessary), probably doesn't need painting and not near as heavy as wood.

Anyway, good luck, it must have taken a lot of effort to get the framing up.

['enry VIII]

Good job! And it's quite large, did you build it from plans?

'enry VIII

[dps]

Looks like it would work but I see a couple things you might want to address.

It appears to have a double ridge pole. This will increase the strength, but when the plastic is on it, rain/snow will accumulate on the flat section on the top. If it freezes, you have a block of ice up there. That's not a problem in itself, but if the ice is thin enough and a wind comes up, it could dislodge the ice (which could have sharp edges) and tear holes in the plastic. Similar things have happened to me when I had an ice storm that accumulated on my greenhouse. Get some UV treated repair tape for that possibility.

The rain is also likely to collect at the bottom of the roof line as the plastic sags. Not really a problem: you can just take a push broom on the inside and bow the plastic outwards to dump the collected water.

It isn't clear from the picture how you are going to provide ventilation when the plastic is on. Ventilation is essential, even in cold weather. A sunny day can bake the plants even if it's cold outside.

The easiest way is to make the sides so that they roll up. Just roll the plastic around some battens at the bottom. The battens should be tied together so that the whole length of the greenhouse will turn and roll the plastic on the batten. At the top, you put some strings that you can use to tie the roll of plastic in place. The disadvantage of this is that you have to be home to watch the weather and you have to be home when the cold night temperatures turn to warm day temperatures (and vice versa). For a sunny cold day, just open the front and back doors to provide some circulation.

A more automated way is to provide an exhaust fan and thermostat. I just put a door on the end that opens inward on a spring. When the fan comes on, it pulls the door open to provide cooling air. This is more work but you don't have to watch it. For a small greenhouse like this you could probably use some cheap plastic box fans (around $20 or less each) with a thermostat built in. Frame them in and put a flap of plastic over the outlet so that they aren't open all the time. I'd use two of them on the leeward end. I had a 30" exhaust fan, so I used it. Bigger is better (up to the point where it doesn't fit onto the end wall). If you use a large exhaust fan, put screen over the fan for safety. It can chop off fingers. If you don't do this simple thing, your homeowners policy may decline to pay for injuries to some kid who wanders into the greenhouse.

A small greenhouse like this can be heated when necessary by a small electric space heater. All you really need is to keep it above freezing. I've used two of them in a medium size greenhouse successfully. Gas or kerosine heaters can be used, but keep all appropriate safety precautions in mind.

[Ignoramus3099]

I would say, let them turn grey.

The columns are made pf 1.5" pvc pipe, yes. This greenhouse is not for winter, it is for planting things on April 1 instead of May 1.

Actually, it did not...

i

[Ignoramus3099]

Thanks, no, I did not build from plans.

i

[Ignoramus3099]

Maybe I will put plywood on top for this reason, good point.

I will add a lot more thin rafters.

Another good point that needs addressing when I put plastic on it.

That's sensible, thank you.

I have a special temperature controlled outlet for that, it turns on at 3 degrees C./

i