Edge Pressure of Insulating Glass Units

Chair
Helen Sanders
Technoform

Project Justification
Excessive edge seal pressure may cause premature seal failure and lead to glass breakage.

Reports to:  Technical Services Committee

Project Product

  1. Identify the causes and consequences of excess pressure exerted on the edge of an insulating glass unit when installed in fenestration systems. Understand the extent of the magnitude of the potential issue.
  2. Document the supporting reasons for the allowable edge pressure range of an insulating glass unit and is it still valid (4 to 10 pli – per linear inch).  Investigate whether the edge pressure required for AWS performance exceeds the maximum allowed IGU edge pressure.  Understand the variation of resistance to edge seal pressure of different spacer and sealant systems.  Also understand if the lower value of 4 pli is appropriate for all glazing systems.
  3. Engage with fenestration and gasket manufacturers to understand the current design specifications for fenestration framing systems relative to delivering the appropriate edge pressure and identify any issues.  Document the findings and provide recommendations.
  4. Identify installation considerations and guidelines for achieving water and air tightness but not over-compressing the edge seal.
  5. Identify tools for measuring IG edge pressure in a fenestration system.

Project Deliverables
Installation considerations and guidelines for achieving water and air tightness but not over-compressing the edge seal.