Help me with my container hoop house
 

I have a large [URL="http://www.tomatoville.com/showthread.php?t=29174"]wooden SIP container[/URL]. I want to extend my growing season by turning it into a hoop house like structure for the month of May. So here is the plan

The container has holders for PVC pipe built at its edges. I am planning to use these holders and construct a rectangular prism structrue 5 ft high, 4 ft wide and 3.5 ft deep using PVC pipe. There will be 6 vertical pipes (one in middle of short side and two on the longer side) and at 5 ft height, they will be capped off by T fittings. And I will use PVC piping and corner fittings to create a rectangle (the same size as the planter) at that height.

I plan to cover this structure with 6 mil poly.

I also have couple of earthtainers I plan to create a similar structure of PVC pipes that will snugly fit those two earthtainers and few more 5 gallon buckets. That will also have 5ft height from the soil level. It will probably be similar size (3ft x 3 ft x 7 ft high)

There will be a temp measurement unit inside which will record daily low and high temps for a week before I actually start using it, that will tell me what temps are reached.

Questions:
The available volume is much smaller than a hoop house/ high tunnel. Will that cause too much humidity, too high temperatures?

Will the plants grow more than 5 ft in one month, what would be ideal height for the hoop house?

How to make this covering easy to roll up and close up? - Or should I use some other material?


In June, when temperatures are higher and plants are higher, I plan to permanently remove the poly cover and add to the structure and make it 10 ft high. On the large container, the structure will act as supporting cage for tomato plants

Thanks for your ideas, suggestions, pointers to something similar you may have done

I use 1/2" emt for my hoop houses. I use snapclamps to hold the 6 mil poly down and it's easy to open/close the hoops. Has worked great for me and has held well even in high winds. Highly recommend the snapclamps.

On sunny days I open up the ends early as it can get hot in there fast.

The lower the volume of the structure, the faster the temperature will swing between extremes. It still works just fine, as long as a lot of attention is paid to venting.

tnkrer,
Here are a couple of pictures of what I do with with my raised beds. I turn the raised beds into small cold frames during the early Spring and then remove the plastic once the weather warms. By using the plastic cover I can also control the amount of water that their receiving. Sometimes in the Spring we can get some heavy rainy spells that lasts for days which can cause stress in the plants. The cover helps to avoid this and gives me an earlier harvest.
With a little experimentation, I'm sure that you will be able to build a cold frame that will help accomplish what you want to do. You only have to protect your plants for about 3 weeks or so before you can remove your plastic and save it for the next year.
dpurdy