Alan Builds His Hoop House - Part 1

Chapter One - The Plan Comes Together

For years I have wanted to build a Greenhouse. OK, that's a bit of an understatement - I actually want to build an awesome, unique, quirky greenhouse out of old windows and other recycled materials. I have already collected a very nice full view storm door (free on craigslist) and eight old windows for this project.

However, Barb and I are planning to move in the near future, so this assembling this structure is currently stuck in the planning (and procuring, if the price is right) stage. I wouldn't dream of leaving it behind and disassembling it, once complete, would be heartbreaking.

Also because of our plans to move, Barb and I have a large number of potted plants. We have a great combination of culinary and medicinal herbs, some flowers and four nice ferns that hung on our porch all summer.  The past two winters I have bought bales of straw and created a cold frame by stacking the straw bales in a large rectangle and covering them with my old windows.  This has worked reasonably well, but we have lost a plant or two each year. 

Over the summer, our collection grew, as we bought or planted more herbs, bought some blueberry bushes at the farmer's market, and Barb was given two nice strawberry plants for teacher appreciation gifts.  Some of our plants - especially my favorite, a very large and fragrant lemon balm - have grown too tall unless I built a much larger structure.  Last year I bought 12 bales from a local farmer for $4 apiece.  This year it would take at least twice as many, costing nearly $100 (and might require more windows). 

As the leaves started to turn and the first frost crept closer, I began to research plans for more permanent and practical cold frames.  I drew up a couple of designs and began researching suppliers and prices of the materials.  I pulled out my copy of How to Build Your Own Greenhouse by Roger Marshall, a gift from one of my daughters last Christmas.  I searched the web for plans and ideas.  Then Barb came home with the October/November 2011 edition of Mother Earth News.  The main cover story read "Build an Easy Hoop House to GROW MORE FOOD." The cover photo showed a very nice hoop house with a PVC frame and clear plastic sides.  That was it.  I was going to build a hoop house.  And it was going to be Easy.

I read the article at least 6 times.  The author, Steve Maxwell, included great advice on placement, materials and step-by-step construction instructions. But there were variables.  A chart on page 43 offered advice on pipe diameters for hoop houses ranging in width from 10 feet up to 18 feet.  According to Mr. Maxwell's diagrams at the bottom of the same page, a 12 foot wide hoop house would be 6 feet tall if the hoops are 19 feet long.  A quick check for PVC at Lowes.com told me that PVC came in a standard length of 10".  By my reckoning, a 20 foot hoop in a 12 foot wide hoop house would yield a center height of just over 6 feet.  Since I am 6' tall, this made the width decision easy - but how long should it be?  Hmmm...

According to Mr. Maxwell's excellent advice, the hoops should be spaced 2 feet apart in areas with high winds or snow loads.  However, in more moderate climates, like here in North Carolina, he recommended spacing the hoops 3 feet apart.  There were two more factors in my length decision.  The first was choosing a length that was a multiple of 3 AND the board was not too long for me to get home.  I drive an extended cab pickup with a fairly short bed.  I decided 15 feet was about as long as would be practical.  The last factor was the plastic covering.   I found that 20' was one of the widths available, which would easily cover the 15' length and have room to wrap around the ends to be stapled to the wooden frame. 

So I had a plan.  (This would not be my final plan, by the way. More in Chapter 2 on this...)  Based on my design, I came up with the following material list:
2 Schedule 40 PVC "T" fittings
4 Schedule 40 PVC Cross fittings
12 Schedule 40 3/4"x10' PVC pipes
24' of metal pipe (big enough for the 3/4" PVC to fit in
2  2"x6"x12' Treated boards
2  2"x6"x16' Treated boards (they don't make 15' boards)
9 Furring strips (I actually needed 10)
16 2"x3"x8' Pine boards (for the end frames and doors - I actually needed 20)
3" deck screws
2" deck screws
A roll of clear plastic at least 20'x50'
2  1"x4"x6' treated boards (for anchoring the frame to the ground)

And I forgot to include:
2 latches and 4 hinges for the door.

Had this been the final plan, my material cost would have been roughly $275, and would have required one trip to Lowes.  However, I have 5 Lowes receipts and a few more chapters to write, so please stay tuned!


Peace and Blessings,

Alan