100 Dollar Greenhouse

These are instructions for a 12' x 14' (168 sq. ft) greenhouse for $100.

This is the materials list:

16 3/4" PVC pipe, schedule 80, 10 ft long (8 ribs for each side)
6   3/4" PVC crosses, schedule 80
2   3/4" PVC tees, schedule 80
32 3/4" galvanized electrical metallic tubing (EMT) straps (clamps)
2 2"x 6" x 14' treated No.2 pine boards
2 2" x 6" x 12' treated No.2 pine boards
4 2" x 4" x 7' treated No.2 pine boards
4 2" x 6" x 6' treated No.2 pine boards
4 4" x 4" x 2' treated No.2 pine boards
2 2" x 4" x 3' treated No.2 pine boards
1 1' x 4" x 12' treated No.2 pine boards (to be cut up for door parts)
1 Set of door hinges
1 sheet of clear plastic, 24' x 20, 4 mil
1 can PVC cement
1 can PVC cleaner
1   1/2' x 10' galvanized electrical metal tubing (EMT)
Misc nails, screws, and staples

Use the EMT Clamps to Hold the PVC Pipe (Ribs) to the bottom frame. The 12' width was chosen so each rib section is 10 ft long.Don't change that ratio or the greenhouse will not stand up under the wind and snow load. use a handsaw to cut the pvc, space the ribs 2 ft apart. The spine will be 22 1/2" sections long. When the spine is put back together with the T's and X's, it will form a 14' spine section. While assembling, place the galvanized EMT pipe into the spine for strength. Cement all the ribs to the spine section, and let dry 1 hour. the 4 -4"x4" x 2' posts are used for the corners buried 1 1/2' deep. the 2' x 6' x 14' are the lengths you want to put the doorframes on, and the 2' x 6" x 12's are the side joists. Make the door frames 3' wide, with the 
door centered on the 14' joist, and the 2' x 4" x 7 the diagonals to the door frame, which are the 2' x 6' x 6" pieces.