Jim Elbrecht wrote:

On Fri, 20 Jun 2008 10:08:29 EDT, Derek Broughton
wrote:

~ jan wrote:

How about instead of thinking on the liner, think under? As in make a
ridge under the liner and lay the liner over it? ~ jan

Doh! Here I am advising him what cement to use, and completely forgetting
that I _did_ that with my bog...

If your @. . .ca address doesn't mislead me, then an under-liner berm
must survive a few frosts. [at least in your soil] Did you use
an underliner of any kind? or reinforce it with newspaper, padding,
mortar or some such?

No, no, no and no. The pond is in extremely sandy soil. In a hole for a
5000 gallon pond, I found one fist sized pebble, and a broken drain tile.
So there was nothing to cause punctures, I was never concerned about frost
(frost heaves only really happen in undrained soil - you need some water to
freeze and thaw). If you're really worrying about heaving under the berm,
dig a hole and fill it with 6" of gravel, _then_ start the berm.

My only other concern would be how it responds to being walked on once
in a while.

That was always my concern - I had no thoughts at the time I dug it about
the fact that sandy soil also isn't self-supporting :-) However, I had
absolutely no slumping of the sides in the time I owned it. Again, when
you have really good drainage, there's no inward hydraulic pressure, so the
water in the pond holds the walls in place. My bog-berm probably did get
compressed a bit, but not significantly.
--
derek