Building a Foundation for your Greenhouse
Pressure Treated Wood Foundation:
A hobby greenhouse under (100 sq. ft.) can be fastened to a 4″ x 4″ or 4″ x 6″ treated wood timber foundation. For a larger greenhouse a 6″ x 6″ beam is recommended. Pressure treated wood now requires a 10 mm polyethylene barrier between wood and aluminum sill to prevent corrosions of aluminum.