- Q.Can 6x6 pressure-treated
deck posts be sunk into the ground or should they be
supported on concrete piers?
A.Theoretically, posts that
have been pressure-treated for ground contact can
be sunk into the ground. However, it is unlikely
that the treatment has penetrated fully through a
6x6. So I would opt for the concrete piers with the
posts supported on metal post anchors.
If the posts are sunk directly into the ground,
the bottom of the post must not be cut. I have seen
a number of posts with the center rotted out
because the treatment chemicals did not penetrate
completely, and water was wicked up through the
untreated center. Post tops should be beveled to
shed water, or have a metal post cap added. Any cut
ends of pressure-treated material that are left
exposed to the weather should be dipped in or
painted with a copper napthenate solution.