3. •Excavate the outside of the wall first,
1 m wider than the hole & track
the tunnel until the middle of the
dam begins.
•Step the sides of the excavated area
inwards, back fill this area with the
same type of clay/soil for
continuity in the wall.

4. •Excavate from inside the dam above the water line,
if the water is not below the bottom side of the hole
you must create a temporary wall to stop any water
entering the wall.
•Start 1m wider than the hole, track the tunnel through
to the compacted part of the back wall, dig wide
enough until you reach the compacted soil
(not water saturated soil).

5. •Leave the top of the tunnel intact if possible for the
integrity of the Wall.
•The sides of the excavation need to be
stepped in like a wedge from the inside
of the wall out.
•This concentrates the pressure of the
water to a smaller area in the centre
of the wall for better holding strength.

6. •The section on the back of the wall needs no
Polymer; it does require considerable
compaction as this area is a back stop for the
material in the middle & front parts of the wall.
•These quantities will be able to be calculated
once the back wall is finished and compacted
once the front half of the wall has been
•excavated.

7. •The internal walls of the tunnel
need to be moistened & dusted
with Polymer to act as an
adhesive for the soil.
•The clay/soil mixture needs to be
lightly moistened to allow the
polymer to stick to the soil, and then compact into the hole
as tightly as possible in 1 cubic metre quantities.

8. •When compacting the clay/soil
into the centre of the wall, you will
require 3 kg of Polymer for every
cubic metre of soil.
•The clay needs to be combined
with a little water so it sticks to
the polymer when combining
them before compacting back into the wall.

9. •When compacting the clay/soil into the front of
the wall, you will require 5 kg of Polymer to
every cubic metre of soil.
•The last 30cm of soil in the hole on the inside
wall needs to have a larger quantity of Polymer
in it to act as a cap.
•Once this is complete, the entire wall needs to
be treated with a liquid & granular Polymers to
secure the surface area of the inside wall against
any water ingress.
•Liquid Polymer sprayed above the water line &
powder/granules spread across the water.