A look at concrete ponds including fibreglass finishing.
A concrete pond correctly built will last for many years. This method pre-dates more modern technique and it does look breathtaking when done well. It also is the only approach if you want the look of perfectly vertical drops and straight edges.However, this method is not for the faint hearted as it isn’t easy. Typically concrete blocks will be used as the foundation (the big grey blocks like you will see when new houses are built). This will then create the basic structure which then needs to be smoothed over and finished with a render. Alternatively, an older technique was to employ wood boxes to utilise the ‘shuttering’ technique – the process of forcing the wet concrete into shape by constraining it by boxing it in with wood panels. Either way a smooth surface is required, so it is not rough for the pond fish. Also the surface must be smooth as a final sealing treatment must be applied to any of the surface due to come into contact with the water. This rendered finish needs to be waterproofed by using an sealant otherwise the pond will not work as the water will escape. A very popular product for this is a moisture cured polyurethane called G4 pond sealer. This product uses moisture in the render and the air to harden. The most popular colour is clear and you will need to apply several layers of this sealant before your pond is ready. It is often worth considering adding fibres into the render mix to prevent the render from cracking in the winter due to frost. Adding such fibres will also give additional strength.
Fibreglass Pond Lining
The basic core construction is the same as for concrete ponds. However, rather than a simple render a fibreglass topcoat provides an ultra-strong smooth, attractive finish. This coating can be any colour but green and black are the most popular choices. The other benefit of a fibreglass finish is that it ensures that no impurities can leach into the pond.