Can curtain wall glass repairs address failed sealed units?

In most cases, a failed sealed unit within a curtain wall can be replaced without replacing the surrounding framing. The appropriate solution depends on the condition of the curtain wall system, the original glass specification and the way the unit is retained within the frame.

A sealed unit may be considered to have failed when its edge seal no longer keeps the cavity airtight. Typical signs include misting or condensation between the panes, persistent clouding, visible marks inside the cavity or a noticeable deterioration in thermal and acoustic performance. Moisture on the room-side or external face of the glass may have another cause, so an inspection is important before the unit is ordered.

During an assessment, GlassPlus UK considers the curtain walling design and checks the opening, glazing beads, pressure plates, gaskets, drainage paths and setting blocks. The surrounding frame is also examined for distortion, corrosion, movement or damage. Replacing the glass alone may not provide a lasting result if the fault is linked to defective seals, worn gaskets or a compromised framing component.

The replacement sealed unit must match the requirements of the existing installation. This can include:

• Overall height, width and thickness, including the cavity dimension.
• The correct glass make-up, such as toughened or laminated glass where required.
• Low-emissivity, solar-control, acoustic or other performance characteristics specified for the building.
• The position and orientation of coatings, spacers and edge details.
• The correct seal, gasket and retention arrangements for the curtain wall system.

Accurate measurements and specification checks are therefore essential. A visually similar pane may not be suitable if it has different weight, thickness, thermal properties or safety characteristics. GlassPlus UK can assess whether the existing unit can be matched or whether a revised specification is needed to maintain the intended appearance and performance of the elevation.

The work generally involves making the area safe, carefully removing the retaining components, extracting the defective unit and installing the replacement with suitable packers, seals and supports. The glazing is then checked for correct seating, alignment, drainage and secure retention. Any damaged associated components identified during the inspection should be addressed as part of the repair rather than concealed by fitting new glass.

Where the curtain wall is part of an occupied commercial building, planning the work around access, protection and the use of the space can help reduce disruption. The required method will depend on the unit’s location, size, weight and the access available at the property. These practical considerations should be established before the quotation is finalised.

GlassPlus UK has more than 30 years of industry experience and carries out commercial glazing work with regard to current building and safety regulations. For a dependable assessment, the most useful information is the location of the failed unit, photographs of the internal and external faces where available, details of any visible markings and an indication of the curtain wall system. A site inspection may still be required before a compatible replacement can be confirmed.