16/07/2026
We where instructed to carry out an independent practical inspection of an affected window opening due to reports of water ingress.
To facilitate a thorough assessment, sections of the external brickwork surrounding the window sill were carefully removed, allowing the construction details within the specified area to be examined.
Our inspection identified several defects that may contribute to water ingress during periods of rainfall:
The damp-proof course (DPC) beneath the window sill had been incorrectly dressed, folding back behind the sill rather than directing moisture externally.
The cavity closer (Flexi closure) had been installed bridging onto the window sill, creating a potential route for moisture to track across the cavity.
No evidence of cavity blockage, mortar build-up, or debris was found within the inspected cavity. The cavity was clear, indicating there was no thermal (cold) bridge within the area investigated that would explain the internal dampness.
An incorrectly specified and inadequately installed wall tie was identified at the window reveal. In our professional opinion, the installation does not reflect accepted standards of workmanship expected on a newly constructed property.
Based on our findings, the defects identified are associated with the construction detailing around the window opening rather than a blocked cavity. We would not have installed a cavity closer in a manner that supported the internal reveal blockwork. Our preferred method would have been to insulate the rear of the window sill, form a concrete bench behind the sill to provide adequate support, and ensure the damp-proof course was correctly installed to direct any moisture away from the internal structure.
This report reflects our findings following an intrusive inspection of the specified area and represents our professional opinion based on the condition observed at the time of inspection.
Gibson's Bricklaying & Build/ Property solutions