which are cypress. But I don't currently have access to a good local supplier of cypress and am wondering what else I can build these out of and keep the weight down. Will P/T pine be too heavy? What are my other options? How long will untreated pine last outdoors, off the ground? The gate posts are 6x6's with a concrete collar. The dimensions are approximately 12' x 3' for the entire gate, ~6'x3' for each gate 'half'. No, I'm not going to paint or stain them.