"Jerrispond" wrote in message
...
Concrete blocks(8x8x16) three high with steel rebar yes,but you should
drill
into the oldslab because it won't bond. Also a 6 inch cove sand around
the
inside
before the liner goes in would support some of the weight.That would be
my
plan,

I agree....you NEED rebar. I don't think it absolutely necessary to drill
into
the base...but it would be better to do it. I think the sand inside is a
good
idea to cushion the bottom of the liner, especially where the block meets
the
bottom base. I assume you will then line it, and put more blocks on the
top of
liner to hold it in place.....Jerri

My greenhouse pond has breeze blocks 2 high with cement joining them as
usuall. This was laid ontop of solid earth! with just a bit of cement to act
as a kind of footings! This all makes a big rectangle. There is a pond liner
on the inside to keep the water in. There are no pins or things stuck in
the ground. But...... The greenhouse is screwed down to the breeze blocks
with six screws.

If I did it againg then I may reinforce it.
If you do build it then if you have your rectangle get the liner and put it
in. Buy some wood and screw it to the liner and through to the blocks. A
kind of edgeing. You could also try stone.

--
SEE YER..
IAN P. GARDNER
SOUTH ENGLAND
ISLE OF WIGHT.
www.gardner44.freeserve.co.uk