Commercial architectural window and door systems in Australia, especially in Melbourne, are often silicone glazed to block the entry of water into the building. However, dry butted frame joints can leak and silicone glazing simply attempts to mask their poor manufacturing, eventually causing problems.

In many ways, this has led to stagnation of improvements in the manufacturing processes, including innovation in window system drainage. Very few companies have seriously addressed the issues related to ‘controlled leakage’. Commercial windows are designed to leak with vertical members such as jambs and mullions acting as downpipes and horizontal members, especially transoms, functioning as gutters. This core principle of drainage through the frame into a subsill is what all commercial framing systems ought to do.

The EDGE commercial aluminium window and door systems come incorporated with a practical and reliable solution to deal with moisture - be it from rain, humidity or condensation.

Watershed is an innovative rainwater window system drainage methodology from EDGE Architectural Glazing Systems, designed to manage and direct the flow of rainwater through the frame system to the external perimeter of the building. The concealed transom drainage system directs water over and around the edge of the glass.

Designed to be factory fitted during transom assembly, the Watershed component increases quality control and decreases fabrication costs for window and door systems.

Once properly assembled, Watershed ensures water cannot run from the end of the transom on top of the glass or the glazing wedge, and also eliminates ugly external drain holes in the face of sills and transoms. The use of silicone glazing in windows will not stop water entry while external drain holes actually become a point of entry for water. Good design allows water entry and effectively deals with drainage.

The Watershed innovation allows safe passage of water in front of the glass, using vertical members (jamb and mullion) to direct water through the system for collection by the subsill.

Traditional ‘roll in’ wedges have been used in the window manufacturing industry since the beginning. Usually manufactured from PVC, roll in wedges are commonplace in the residential window industry, but have a poor reputation in the commercial market, as PVC shrinks and a roll in wedge can quite easily roll back out.

EDGE Architectural systems use high performance, purpose designed seals that won’t shrink, are UV stable and cannot fall out once properly fitted. EDGE’s framing gaskets are uniquely top loaded into the frame, and manufactured from co-extruded Santoprene with a rigid backing, which gives audible feedback when being fitted.

The gaskets can be used on both sides and treated as a captive or roll-in wedge in one. It fits relatively flat into the pocket and is easily fitted in the factory or on the project site. The wedge gives an audible click as the co-extrusions key into the pocket, ensuring the wedge is properly seated. Santoprene is the best material available for long-term durability and anti-stretch features. The co-extrusion backing gives an easy identifier of thickness and further enhances the anti-stretch capabilities of the wedges. The top-loaded pocket was designed for fitting the glazing wedges. Additionally, the wedge cannot be dislodged during glazing.

The inner leg on the pocket is lower than the face of the frame, giving a perfect detail to run a bead of silicone prior to fitting the inner wedge. With the leg lower than the face of the frame, there is less chance of ooze.

Key benefits also include a clean and uncluttered pocket design with no restricting legs inside; back of the pocket 5mm wider than the gap, making it easier to angle glass into the pocket; and pocket depth 28mm on deep and 17mm on shallow, allowing for a full 12mm glass bite and edge distance requirement as per AS4555 (insulated glass units) Table E5.1.

The anti-drop out glazing beads lock into place by locating into a captive groove under pressure from a glazing wedge or foam rod in the pocket. Glazing beads can be used on the underside of transoms, ensuring water is better contained within the glazing pocket. The anti-drop out bead prevents dislodgment, a feature not available in any other commercial aluminium window and door system. For greater flexibility in manufacture, most suites can be internally or externally glazed.

The Watershed window system drainage methodology from EDGE Architectural ensures dry interiors and prevents build-up of still water, recurring condensation and even mould that can occur in standard framing systems.

Image: A fresh take on glazing and drainage methodology