I just joined the site and have found much needed info and ideas here, the topic of using treated lumber has come up in a few of the post I have looked at but heres my questions. 1 How long will it take for the treated wood to cause corrosion and 2 if the aluminum that is in contact with the wood has a good coat of paint on it will it even be affected. I ask this because 2 1/2 years ago I built a new deck on my home and used painted aluminum that I bent in a break to make a cap to cover rim joists of the deck to match the house and after inspecting it I see no corrosion. The aluminum on the boat is heavier than the flashing so do you think a good coat paint is all thats needed? I can see the manufacturer of the lumber putting out the warning not to use aluminum nails because a house should last a lifetime and if the nails corroded in 10 - 15 years it could make the home structurally unsafe. Does anyone know specifics on this how long it takes to corrode a nail or sheet metal thats exposed to the lumber???