A greenhouse is typically an enclosed structure with glass walls and a roof, meant for growing fruits, vegetables and plants. It absorbs the heat of the sun to provide the contained plants a controlled and safe environment. Gardeners who want to get a head start on the production of a particular fruit or vegetable, or extend its growing season prefer greenhouse gardening. You can build your own greenhouse in a corner of your yard with a few old windows and some inexpensive materials.
Collect old windows so you can determine the size of the greenhouse. Select a sunny spot in your back or front yard and measure it. An 8-by-10-foot greenhouse that is 10 to 12 feet tall provides space for up to 100 plants. Demarcate the area with spray paint or powdered chalk.
Dig a one-foot-deep trench that is two-feet wide along the demarcated line with a shovel, and collect the dirt in a wheelbarrow. Lower concrete footing or rented prefab forms into the trench. Support them with steel rods or rebar tied both vertically and horizontally to the forms.
Allow up to ½-inch D-anchor bolts to hang from the top of the footing as you pour concrete. These will help secure the walls of the green house to the foundation when you install them later. Also allow for two- to three-inch drainage holes, spaced three-feet apart in the foundation. Remove the forms only when the footings cure thoroughly.
Dig a five- to six-inch trench for the greenhouse flooring, and level it with a shovel so it is even. Also spread and level a four-inch layer of gravel into the trench. Spread tar paper over the gravel to form a vapor barrier before spreading a two-inch layer of sand over it.
Lower flooring bricks into place, packing them tight against each other so seams are flush. Spread a fine layer of sand over the brick floor and sweep it so it fills any visible gaps.
Use the protruding D-anchor bolts to secure vertical 4-by-4 posts to the foundation. Saw the tops to allow for a slope that assists drainage.
Hold 2-by-4 lumber boards for the walls against vertical posts and nail them with galvanized wood screws. Also nail the wooden roofing framework into place after assembling it. Cut roofing felt to size and spread it over the framework. Nail it in so it is secure.
Hold your old glass windows in place at the sides of the greenhouse and nail them in so they are secure. Your greenhouse is now complete.