Leaking windows after rain: The window or the surrounding wall?

Windows leaking when it rains do not always require complete window replacement. Water visible at a sill or reveal may originate within the window, around its installation or elsewhere in the surrounding wall. The repair should follow the water path that evidence supports.

Start by recording the affected opening and conditions. Repeatedly sealing visible joints without understanding the assembly can leave the source unresolved and make later investigation harder.

Make the leak record specific

Identify the room, elevation and opening, with photographs showing both the wider location and the affected detail. Note when water first appears, the weather conditions, where it is first visible and any previous repairs. Record whether nearby walls or ceilings are also affected.

Keep observations separate from conclusions. A stain below the window establishes where moisture became visible; it does not prove that the nearest joint is the entry point. Where water creates an electrical or other immediate hazard, arrange the appropriate urgent response.

Examine the window and its installation together

The investigation may need to consider the frame, operable components, glazing arrangement, drainage provisions, perimeter connection and adjoining wall. Ask which elements can be checked safely without opening finishes and where further access is needed.

The Australian Glass and Window Association selection guide addresses installation and flashing as part of window performance. Product selection alone does not establish how the opening connects to the building’s weather-management layers.

Investigate the surrounding façade

Consider connected cladding or masonry, flashings, penetrations, balcony interfaces and the area above the opening. Existing drawings and installation photographs may help explain concealed details. If those records are absent, identify that limitation rather than assuming a standard arrangement.

Where controlled testing is proposed, ask for a method that isolates questions and records conditions and results. Uncontrolled hosing can introduce water through multiple routes and produce misleading evidence. Testing should be planned and undertaken by competent people for the actual building.

Choose a repair boundary from the findings

A local repair may be appropriate where the failed element and surrounding condition are established. A broader opening or wall repair may be needed where the interface is defective. Window replacement may be justified where the unit or overall arrangement cannot meet the required outcome.

• State the identified cause and supporting evidence.
• List the components to retain, repair or replace.
• Identify how the new work connects to retained elements.
• Record uncertainties and the response if they are encountered.
• Define inspection and testing before finishes conceal the work.

If replacement is selected, continue with SCE’s strata window replacement planning guide for opening schedules, procurement, access and handover.

Coordinate access and strata decisions

In an apartment building, the investigation can involve access inside a lot and outside the façade. Confirm the authority for work, resident arrangements and the relevant property records. Technical source identification and legal responsibility are separate questions; obtain the appropriate strata or legal advice where responsibility is disputed.

Arrange protection for furnishings and finishes, and document any temporary measures. A temporary seal or covering should have its purpose and limitations recorded so it is not mistaken for an accepted permanent repair.

Verify the repaired opening

Agree what inspections, tests or subsequent observations will support completion. Retain the detail, products, photographs, test record and any limitations. Update the building’s maintenance information where components or access requirements have changed.

SCE’s façade portfolio provides evidence of connected envelope construction. SCE delivers investigation, engineering, design, procurement and construction within the agreed appointment, with independent certification and statutory functions assigned appropriately.

Request a Project Suitability Review with the opening locations, weather history, photographs and available building records.