tomf wrote:Pressure treated at the bottom, then dug fir, it will e I side so rot should not be a problem. The exhaust fan is can circulate more air than the highest estamate for it's volume as calculated for a greenhouse. Also there will be two industrial fans inside and air intake vents. I may paint it white.
Not much Douglas Fir around these parts but I have the feeling it is not a cheap wood to build with. I know we have trim lumber in fir and that stuff demands a premium, especially stain grade select wood.
I don't know if you've ever painted treated wood, but it usually is a bear to keep paint on it in my part of the world. It is best to let it dry as much as you can allow it to, then put a good prime coat on it followed by the top coat paint. Even then, it is a junk shoot as to whether it will stay or not. I prefer to either spray or brush on one of those waterproof stains as opposed to painting it. That seems to absorb better into the wood and doesn't layer up like paint will.