Fixing a flat roof water leak at roof junction

The issue: Flat roof water leak

Our client contacted us after noticing persistent water staining along the junction between their pitched roof and adjoining flat roof. Intrusive inspection revealed the underlying cause was capillary absorption combined with wind-driven rain penetrating a vulnerable joint detail. The client requested a full remedial solution to prevent ongoing water ingress and future damage.

Following a full inspection, we provided a detailed quotation outlining the recommended remedial works. Once approved, the project was scheduled to commence promptly.

Works Completed

Our expert roofing team began by stripping back the affected roof area to access the junction fully and expose the underlying substrate. This allowed us to address the root cause rather than applying a temporary surface-level fix.

We then redesigned and strengthened the junction, implementing the following key works:

• Upgraded edge detailing between the pitched and flat roofs to improve resilience against water ingress

• Installed a multi-layer waterproofing system, providing long-term protection against driving rain and moisture penetration

• Enhanced flashing and junction protection, ensuring a fully sealed transition between roof types

• Incorporated additional measures to prevent moisture tracking beneath tiles

All work was carried out using high-quality roofing materials and techniques, ensuring a durable and long-lasting solution.

Outcome

The junction is now fully weatherproofed, with a robust, layered defence against capillary action and wind-driven rain. The original water staining issue has been permanently resolved, and the roof now benefits from improved long-term durability and performance.

By addressing the problem from the substrate up, this solution significantly reduces the risk of future water damage and enhances the overall lifespan of the roof.