6X6 vs 5X5 :) a question please :)

[Cyric30]

Hello One and all

Im doing some hunting at the local lumber yard and this is what im finding

while most places have 6x6 post they are only light treaded Ie. like most treated lumber, but from my reading on post & Pier foundation you want wood that is Heavy treated suitable for below ground use. What they do have is 5X5 Post 14 to 20 feet long the 14" being under 15.00$ treated for use in Pole Barns and such and they claim these are heavy treated post (i tend to believe them, the just Look treated heavier)
My situation Is i plan on using P&P foundation on a 1 1/2 story home from plans Here, With the only major change being the addition of a Gambrel Roof
My question are
1: Would these 5x5 be ok to use.?
2: what modifications would i need to make to my foundation plans to use them
3: would this be a resonable alternative to 6x6s
4: your thought and comments please

Thank you all for your time and help

Joe

[Willy]

If the post are treated for that use they will have a tag on them showing .60 percent retention min. Just because they look treated they may not be approved for code. One thing to remember is this is your foundation and it better be right. My 6X6 treated posts 8 ft long are costing 22.00 each but are certified for the use. Mark H.