Peter, rebar is steel rod that you put into concrete footings and is
available at most building centers. (reinforcement bar) As for the drilling
into the old slab. Mortar does not adhere well to old concrete. Drilling
holes and putting rebar in the holes through the first row of block will
keep the weight of the water from pushing out the wall. Also the cove of
sand at the base displaces much of the weight. This is also recommended for
swimming pools and is why dams are thicker at the bottom.
"Peter" ] wrote in message
news:kxAkWpD0hM2+EwXw@nospamwantedherethankyouvery much.com...
Hello Jerrispond,

You wrote:

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.

What is rebar please?
--
Peter