Large insulated glass units; what should you pay attention to when bidding?

1. Glass Layer Thickness for Wind Load Resistance

→ Did you know that thicker glass doesn't necessarily have to be on the exterior?
Contrary to popular belief, just because the wind is coming from the outside doesn't mean the thicker glass in the sealed unit has to be positioned on the exterior.

Considering that thick glass with low-E insulation is very expensive, if the low-E is on the exterior, the thick glass can be positioned on the interior.


2. Position of Setting blocks and/or Reinforcement in Horizontal Mullions

When the glazing is heavy, the horizontal mullion deforms.

This deformation should generally be limited to L/360 or a maximum of 3 mm.

To meet this requirement, the setting blocks can be moved closer to the corners of the glazing, but never closer than 150 mm.

It is also possible to add a steel reinforcement to the horizontal mullion.

3. Glass Tint

→ If a 10mm glass layer and a 6mm glass layer are required on one or more large sealed units of a curtain wall, a difference in tint compared to the other 6+6mm sealed units may be noticeable. This should be validated with a sample and/or mock-up.

4. Spacer, Gasket, and Thermal Break Thickness

→ If you maintain the same finished thickness of the sealed unit with thicker glass, the spacer thickness will be reduced. This could affect thermal performance... to be validated.

Alternatively, when changing the finished thickness of the sealed unit, it is essential to ensure that the curtain wall can accommodate the change. Changing the thicknesses of the gasket and thermal break can sometimes be challenging.


5. Lifting Equipment

→ The weight of the glazing could significantly affect the equipment needed for installation. Lifting equipment (crane or other) may be required for installation... this should be added into the costs.

Disclaimer: This is provided for informational purposes only and each project must be reviewed by a qualified engineer