Build A Leanto Green House

Building a lean-to green house will enable you to grow your own seedlings and extend the life of your plants.

If you have basic carpentry knowledge, you will be able to build a lean-to green house. A lean-to green house can be built very elaborately costing thousands of dollars or economically by simply building a wood frame and covering the exterior with heavy plastic or corrugated fiberglass panels.

The basic points to remember when building a lean-to green house is location and ventilation. Most important is location as you will want to get the maximum exposure to the sun in early spring and late fall. Ventilation is also important in that the green house requires air circulation to grow healthy plants and prevent the growth of bacteria, moulds and disease. Ventilation also controls the temperature inside the green house. The ideal location to build a lean to green house is on the south side of your home. During early spring and late fall, this is where you will get the maximum exposure to available sunlight.

To build a lean to green house 5 feet by 8 feet mounted on a wood foundation, you will start by digging in the foundational trenches. Measure out 5 feet from the house as the width and measure also a length of 8 feet. Using wooden stakes and a string line, mark the foundation out.

Following the string line dig a trench wide enough and deep enough to accomodate the foundational planks. Railway ties or eight inch by eight inch pressure treated timbers make good planks for the foundation. When trenching, use a level and only dig as deep as necessary. It is best to have the foundation on firm soil so do not over dig and have to re-fill. Once the trenches are dug out, lay in the timbers or ties. Again measure the distances width and length and adjust accordingly. Using a large carpenter's square, check to make sure the timbers are 90 degrees to each other and check for level again. Finished, the foundation should look like a large garden plot bordered on three sides by timbers and adjacent to the house.

Once the foundation is set, framing begins. Framing lumber can be spruce or cedar two inch by two inch or two inch by four inch. Install a ledger board on the house. Measure from the soil 7 feet and mark a line on the wall. Using a level, draw a line acrossed the wall 8 feet the length of the green house. Nail or screw a two by four along the line. Make sure the end of the ledger board is in line with the foundation. For accuracy use a plumb bob. Once the ledger board is secured, the next step is to frame the three exterior walls.

Build the outside wall first. Cut a top and bottom plate to 8 feet long. Mark the boards off every 16 inches. Cut the required number of studs needed at 6 feet, and nail in the studs on center.

With the wall now framed, measure corner to corner and if the distances are equal, the wall will be square. Nail two scrap boards diagonally across the wall, stand the wall up on the foundation and nail or screw it down. Support the wall to the ground using a couple of studs. Using a level, check to make sure the wall is straight. Nail a rafter on each end of the wall up to the ends of the ledger board. Now nail in the remaining rafters at 16" center. With the outside wall and roof framed, you are now ready to frame the end walls. An entrance door will be installed on the west wall. Mark out an opening 20 inches wide in the center of the west wall foundation. Frame this opening in from the foundation to the rafters. This will be used as the door jam. Nail in the remaining studs at 16 inch center and nail in a header board at 6 feet high in the doorway opening. Build the actual door frame 19&1/2 inches wide by 5 feet 11 inches high. Cover the lower part of the door frame using a sheet of 1/4 inch plywood to fit. The plywood will add strength to the door. Attach the door frame to the jam using a couple of hinges. Now complete the framing by filling in the east wall, again spacing the studs at 16 inch center.

Build three vent doors 14 and 1/2 by 12 inches. Two will be used on the lower west wall and one in the center of the roof. Frame in the vent doors in the west wall about one foot above ground level and center for the roof vent. Install the frames using two hinges each.

Now that the framing is complete, cover the green house with heavy plastic or fiberglass panels. A staple gun works well for installing the plastic. Staple it down tightly to prevent the wind from damaging it. Fiberglass panels can be installed using large headed roofing nails. To finish, you can attach levers to the vent doors by using 1 by 1 and 1/2 inch pieces of wood, drilling holes near the ends and using wood screws to fasten them to the frames.

© High Speed Ventures 2010