Choosing float glass thickness is a design and fabrication question, not a decision based on panel area alone. The specification should connect the glass type with span, support, exposure, loads, edge condition, processing and the safety strategy for the complete assembly.
Architects, contractors and purchasing teams should prepare the information a glass supplier needs. It does not replace structural calculations or the requirements of the local building code.
Start with the panel and support conditions
Record the panel length, width, shape, orientation and quantity. Then describe whether the panel is supported on two, three or four sides, fixed with channels, clamps or point hardware, or installed as part of a façade or partition system. The same nominal thickness can behave differently when the span and support arrangement change.
Consider the complete glass build-up
For monolithic float glass, review the required thickness, processing and installation conditions. If the project uses a laminated construction, review both glass plies, the interlayer and the edge condition. The final selection may involve Laminated Glass rather than a single pane, especially when post-breakage retention is part of the design objective.
Processing can affect the specification
Holes, notches, cut-outs, polished edges, heat treatment, coatings and lamination all need to be considered before production. Send the latest drawings and identify which dimensions are fixed. A manufacturer can then clarify the information required for cutting and processing.
Thickness questions to include in an RFQ
- Panel dimensions, shape, quantity and tolerances.
- Support and fixing conditions.
- Indoor or outdoor exposure and temperature conditions.
- Glass type, interlayer and heat-treatment requirements.
- Holes, notches, edge finish and installation interfaces.
- Applicable design standard and project engineer review.
Get a drawing-based recommendation
Do not choose thickness from a generic chart when the panel has unusual supports or processing. Contact TopoGlass for a drawing-based quotation and include the project conditions.
Start with the support geometry, not a rule of thumb
Thickness selection depends on the clear span, support condition and panel orientation. A vertically supported infill, a shelf and a point-fixed panel do not behave in the same way even when their face dimensions are similar. Record the support lines and the unsupported dimension on the drawing before a build-up is proposed.
Separate nominal thickness from the complete build-up
For laminated or insulated assemblies, list each glass ply, interlayer or cavity separately. The total thickness alone does not describe stiffness, edge appearance, weight or the processing sequence. This distinction is useful when comparing a monolithic float panel with an assembly that uses heat-treated glass.
Account for processing constraints before the specification is fixed
Holes, slots, notches and edgework can change what is practical for a panel. Confirm their location, finished dimensions and relationship to supports before treating the nominal thickness as final. Where safety performance or structural capacity is involved, the responsible project engineer should make the final design decision.
Create a thickness-review data sheet
A useful review sheet records panel size, clear span, supports, application, loads, glass build-up, processing, edge condition and the governing project standard. See custom float glass RFQ preparation for drawing inputs and the float-versus-tempered comparison when heat treatment is part of the decision.
When the order will be sourced internationally, use the China float glass manufacturer evaluation guide to keep the technical review and quotation scope comparable across suppliers.