How to build a greenhouse
STEP 1. The greenhouse base
Use 4" x 4" (100 mm x 100 mm) treated, or natural decay-resistant, sawn wood to make the base.
Make a rectangle 8ft" x 10ft" (2400 mm x 3000 mm) as shown in the drawing above. Fix the wood together in the corners by using galvanized nails and nail plates.
Before you site (position) the base, make sure the ground where the base will rest is level and firm.
Use a level or a water level to check the grade, and dig accordingly to level the ground directly beneath where the wood will be sitting.
Go to www.buildeazy.com/waterlevel.php for an article on 'how to make and use an inexpensive water level'.
Check that the two diagonal measurements are equal. If they are not, make any necessary adjustments. When the diagonals are equal, then the base is square.
Secure the base in place by driving stakes into the ground around the perimeter.
Nail the stakes to the base and cut flush any stakes protruding higher than the base wood.