How to Build a Greenhouse From PVC Pipe

A simple greenhouse can be built easily by two people in several hours using hand tools and materials available at most building supply stores. This is a relatively inexpensive project and should cost around $100. A small greenhouse is useful year-round for starting plants earlier in the local growing season and protecting sensitive plants from the elements.

6 pressure-treated boards, 2 inch by 4 inch

4 steel fence posts

10 PVC pipes for hoops, 20 feet by 3/4 inch

10 PVC joints, 3/4 inch

PVC cement

20 hanger brackets for metal pipe, 3/4 inch, with screws

2 galvanized metal pipes, 10 feet by 1/2 inch or 3/4 inch

10 feet of 12-gauge metal wire

100-foot roll of UV-resistant greenhouse plastic 4 mil thickness minimum

Staple gun and staples

Small box of 2 1/2-inch coated wood screws

Determine the size of the greenhouse. By using 20-foot PVC lengths, this will determine the height and width of the greenhouse. This size is determined by available material sizes. It will be 10 feet high and 10 feet wide. The length will be determined by subtracting or adding hoops and planks. The materials list is for a 10-foot-high by 10-foot-wide by 20-foot-long greenhouse. This greenhouse design maybe extended past the 20-foot length by adding segments of frame and PVC rings.

Choose a level, well-drained area for the greenhouse. Place it in partial shade, preferably on the north side of a large deciduous tree. If this is not available, use a shade cloth or a white plastic cover to control the amount of sunlight. Access to running water and electricity will be convenient.

Unless the site is very flat, level the foundation boards. Dig a trench if needed. The foundation boards should contact the ground for a good seal. This is important for both temperature and humidity control. Anchor all four corners of the greenhouse with steel fence posts. Tie these posts to the PVC frame using the metal wire after step four.

Lay all parts of PVC ribs out on a flat surface for assembly. For the ribs to be 2 feet apart, the mid-rib pipe must be cut into pieces about 22 1/2 inches long.

Cement all joints and allow a few minutes to harden.

Position the entire assembly over the foundation boards, bend the ribs, and secure them in place with the 3/4-inch metal pipe hanger brackets with screws.

Add galvanized pipe to the inside of the mid-rib and secure it to the PVC with metal wire. This will add strength to the structure.

Cover the frame with plastic. To secure the plastic, staple it to the foundation frame. Extend the plastic several inches past the bottom of the foundation boards and cover it with packed soil to prevent burrowing animals and rainwater from seeping under the walls. On one side, leave an overlapped flap for a door.

Populate the greenhouse with plants.

To control the humidity inside the greenhouse, use a mist setting on a garden hose.

During the summer months, prop the door flap open to lower the temperature.