It is not possible to say precisely how long installation takes. But installation will normally take about 30-60 minutes. Installing WaStop is usually a very simple matter requiring few tools and a minimum of effort. Many people can install WaStop valves themselves without needing to contact an external contractor. There are non-return valves that cost less than WaStop in terms of the purchase price but that are harder to install, leading to a high total cost for the valve.