On Mar 31, 1:36 pm, wrote:
You have all been most helpful!

I've been thinking about this on my lunchtime stroll to the shops.

I think I will build a box the rough height and width I want out of
bricks.

Sounds good

This allows me to fill the box with logs. A space to be used
by critters at some point I hope.

Whoa, logs will rot out , natural log pile somewhere mebbe but not
supporting a waterfall.

I can then shape around this with concrete.

Dont want no stinking concrete, compacted soil and bricks are just
fine.

Once the rough shape is
done, I can put down some of the underlay, some thick liner (I found
1mm rubber one) and then another layer of underlay,

Geotextile or landscape fabric is what your after,stops root invasion
into the liner, not frost protection fleece which is a lot thinner,
under the liner.
Use sand as well to form shapes and iron out creases.

Liner is matter of budget, polythene wont last more than a season dont
bother.
PVC is pretty good on the price/performance ratio but isnt very
stretchy,creases rather than moulds, and isnt very patchable if it
needs repair.
Synthetic rubbers like Firestone is pretty good.
Butyl rubber comes in various grades , some butyl rubbers dont have
very much butyl in them, it stretches, is repairable and lasts for
ever, it costs as you would imagine. One of many:

http://www.pond-liners-pumps-filters.co.uk/

then finally more
concrete to hold the rocks in place. Enough [real] rocks and pebbles
and you will not see the main structure.

Look at the pictures on Paul Dyer`s site , lots of flat rocks that
will stack, not random shaped rocks that end up looking like a pit
bing.
Natural stone paving slabs break up nicely for things like this and
the rustic edging stones.
Again geotextile where you need it to stop rocks puncturing liner and
just enough sandy mortar mix to hold the rocks in place , concrete is
for motorway bridges.

What about concrete cracking? Would the fact that the liner is between
two sheets of underlay resist tearing? Small cracks I would imagine
would survive. Greater than 1mm I have a bigger problem.

Dont use concrete ;-)
Underlay is always a good idea, geotextile not old carpet it rots.
Make sure your liner is well supported in firm soil with a layer of
sand and underlay and it wont tear unless you put a fork through it.

Concrete ponds almost traditionally leak and are often coated in G4 to
kill the porosity

http://www.arghamvillage.co.uk/produ...tails/180.html

Bit evil to use though as its moisture curing dont want to spray it.

Easy solution don`t use cement for sealing ;-)


This will be the waterfall as well as the cascading stream down to
pond 1. I can then have little stream to pond 2. Finally, I like the
idea of the 3rd pond. Very neat. It'll have to be = pipe volume +
Stream volume + Waterfall volume.

Remember to put plumbing and wiring in for lighting before you start
mortaring things into place....

Adam


Thanks for the links and info. Plenty reading for me to do

In my mind's eye, I can see this clearly. Now to implement this!
Anyone got any spare time? I have many spare beers (Well, not spare
but willing to share) and lots of food. I'll provide everything, you
provide help / expertise

Cheers,
Crispin