On Wed, 12 Apr 2006 10:53:41 -0400, "Don Phillipson"
wrote:

Problem: deck surrounding an above-ground pool
(deck standing on wood posts into sand without
appropriate foundations) has sunk badly at one
corner, has sunk 9 inches at the pool edge, and
17 inches at the outermost corner. Thus the corner
post has sunk about 17 inches and two or more
intermediate posts about half that.

(This deck & pool are about 19 years old and
I contemplate repacing both whenever the
pool collapses . . . I.e. repairs should last two
or three years.)

I plan to raise the deck and support it by
a new joist of doubled 2x6" cedar (i.e. 4x6" total)
diagonally under the corner, and supported at each
end by new posts (4x4" lumber) on 2ft concrete slabs
atop the ground (sandy soil). The deck must first be
raised by one or two auto jacks, placed atop 12" drums
cut from a large poplar tree (2 ft. diameter.)


If the deck is sagging because the supports are sinking,
why do you want to mess with adding beams and other posts?

Just dig out around the sinking posts, jack them back up,
and pour a bigger footing under them. Failing that,
for a 3-year repair, you could probably get away with
just jacking the corner up, and bolting a pair of 4'
cross-peices to the post, at ground level, as an extra
bearing surface.