Tim Downie wrote:
I'm in the process of taking down a hedge and putting up a new fence
and I've found that in some areas, the ground is waterlogged to
within a couple of inches of the surface.

The plan was for a ranch style fence with 4"x4" tanalised posts at 6'
intervals and I'm wondering what's the best way to set the posts to
give them the greatest longevity.


What kind of longevity are you expecting in waterlogged ground? - I estimate
5 years maximum, and I don't believe the 'tannalised' part makes much
difference - you may get up to 7 or 8 years, provided you soak the last 18
inches in creosote for a few days prior to planting - this isn't as hard or
complicated as it sounds - you need a length of 100mm plastic pipe with a
stop end, a plastic bag that fits inside it and a few gallon of creosote
(creosote substitute now, but it's basically the same stuff).
Fit bag inside pipe, stand in one post, fill to top with creosote and leave
for 48 hours - if the stop end of the pipe is watertight you can do away
with the bag.

Given that they're bound to need replacing at some point, should I be
thinking about making them *easy* to remove (by, i.e. setting them in
gravel) or are there other things I should be considering.


Lean mix concrete might be better, IE 10 gravel, 6 sand, 1 cement - just
something that won't wash away, but will be easily broken up when the need
arises - it will also allow water through, which is important with wood -
it's the cracks which appear in hard concrete around the base of the
shrunken timber which hold water and cause end rot - soft, gravelly concrete
eliminates this but still adds mass to the bottom of the post for stability,
also, mix it completely dry - no water at all.


HTH