Building A Waterfall.
Building a waterfall we would normally only cement in the key rock and then
stack the remaining rocks on these key rocks but it does depend on how
steep the water fall is.1 to 4 cement and sand should be fine.When the water is switched on the cement will release lime into the pond even when its dry so its worth leaving it to dry and then sealing it with a water proof sealer available from a builders merchant. For further information: Click Here