A water test is the traditional pressure test for new gravity drains, in which a section is sealed at the lower end and filled to a defined head of water, typically 1.0 metre, before being monitored for loss over a fixed period. The acceptance criteria are set out in BS EN 1610 and depend on pipe diameter and length. The method is straightforward, repeatable and well understood by qualified engineers, and is widely used on London new build projects, drainage adoption schemes with Thames Water and significant repair works. Where access or environmental conditions make a water test impractical, an air test under the same standard is used instead. A clear written record supports sign-off under Building Regulations Part H and any subsequent adoption agreement with the sewerage undertaker.
Water test (drain)
Pressure test using a controlled head of water to check drain watertightness.
