I don't know about timber treatment standards in the us but a great deal of
the timber used here in New Zealand for building is pine, treated to
different levels depending on what you are using it for....

Our highest rating is H5, which is for timber in constant contact with the
ground (house piles, veranda posts that are embedded in concrete, or posts
for carports, fence posts etc) which meets the 50 year durability rating for
our building code.

Lower ratings are used for things not in contact with the ground such as
framing, fence palings etc.

Richard

"G Pearce" wrote in message
...
My deck is ~ 12 yrs old and I just replaced some of the top boards and 2
of
the 2X8 joists 5/4 X 6 top boards ( screwed down) I just wondered what the
life span is for pressured treated wood - I didn't think I would have to
be
replacing them this soon
Gale :~)
"Phyllis and Jim" wrote in message
ups.com...
We used 2x6 for the top and 2x8 for the joists, set at 24" intervals.
They are screwed down rather than nailed.

Jim