Overview
- Primary topic
- Snow load
- Engineering basis
- Horizontal glass
- Review status
- Project-specific verification required
Self-Weight and Snow
Because the pane is horizontal, VitraLab includes glass and selected interlayer self-weight. The governing combinations therefore contain dead load together with the entered snow action.
Action-Dependent Laminated Response
The permanent and snow portions retain their own load-duration and equivalent-thickness bases. The run reported a snow design resistance of 11.250 N/mm² for the selected annealed PVB build-up.
Engineering Review
ULS and SLS Results
The governing ULS combination produced 6.730 N/mm² stress and 0.598 utilization. The governing SLS combination produced 2.052 mm deflection against the 18.462 mm displayed limit.
Serviceability
For horizontal glazing, verify the calculated deflection under the governing SLS load combination against the applicable project serviceability limit.
Worked Example: Horizontal Glass 8 / 1.52 / 8
The snow value is illustrative and must be replaced by the applicable project action.
- Pane size
- 1200 × 1600 mm
- Orientation and support
- Horizontal, four edges supported
- Build-up
- 8 + 1.52 + 8 laminated glass
- Glass and interlayer
- Annealed float glass, Family 1 PVB
- Applied action
- 0.75 kN/m² snow plus self-weight
- Selected duration
- Snow load, short-term (1 week)
- Governing combination
- 1.35 Dead Load + 1.5 Snow
- Design action
- 1.687 kN/m²
- Calculated response
- 6.730 N/mm² stress
- Utilization or ratio
- 0.598 utilization
- Governing combination
- Dead Load + Snow
- Design action
- 1.166 kN/m²
- Calculated response
- 2.052 mm deflection
- Utilization or ratio
- 0.111 of 18.462 mm limit
Snow duration, interlayer family, self-weight allowance, pane supports and the project deflection criterion can materially change the result.
Horizontal Laminated Glass Response
VitraLab load, stress and deflection views for horizontal four-edge supported laminated glass.
Swipe horizontally to view more figures
Frequently Asked Questions
Why is dead load included in the snow combinations?
The example pane is horizontal, so its self-weight acts together with the selected snow action in the relevant ULS and SLS combinations.
Does VitraLab determine the project snow load?
No. The snow action and duration must be selected from the applicable project loading basis.
Can the same result be used for a different interlayer?
No. Interlayer family, load duration, temperature basis and build-up affect the laminated equivalent-thickness response.
Engineering content is prepared and maintained by VitraLab Engineering. Worked examples show how the current calculator treats a defined case; they do not replace project-specific verification.