Missing or discontinuous cavity tray over an opening
What it looks like
Water staining above windows, doors or at the ends of lintels, typically after wind-driven rain rather than in still conditions.
Why it happens
No tray fitted above the lintel, trays lapped the wrong way, or stop ends and weep holes omitted so collected water has nowhere to discharge.
What it costs if it is missed
Water discharging into the inner leaf above openings — plaster damage, spoiled decoration, and in severe cases corrosion of lintel bearings.
How to inspect for it
Check before the lift above the opening is built: tray present and continuous, minimum 150mm upstand, stop ends fitted at both ends, weep holes at maximum 900mm centres and at least two per opening.
How to prevent it
Order trays with the lintel schedule, fit stop ends as part of the tray installation rather than as an afterthought, and hold the wall until the tray is inspected.
Basis in regulation
Last updated 23 August 2026. This is our editorial summary of publicly available regulation and site practice, not building control approval or a warranty determination.