Harry K wrote:
Joseph Meehan wrote:
BF wrote:
I have an old wood fence that finally died in the usual fashion --
the posts rotted at the base and broke. Part of the fence is on
concrete slab, and I was wondering if it is possible to extract the
broken-off part of the posts from the existing post holes, and set
the new posts in the same holes? Or will I need to do some
demolition work on the slab and set the new posts in new concrete?

Thanks for any advice,
Rick

There is no good way of doing this.

BTW, while it depends on the area, it may be better and result
in longer lasting post to not use concrete and put the post directly
in the ground. Concrete sometimes traps more moisture and caused
post rot.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

It is possible but... Start by digging out any remains of the rotted
posts. You will then have to use undersized, or trimmed to undersize,
posts. Lot of work and you will wind up with loose posts unless you
can find some type of filler that will set up solid. Better would be
to use post anchors in the holes (if they will fit) set in fresh
concrete. If they won't fit, use metal pipe (again set in concrete)
and face them with boards.


Second. Dig out the wood. Put in a metal post. Add more concrete.

The problem disappears. Forever.