Glass · Projects

Glazing schedule checker

One pane is a calculation. A facade is forty of them. Paste the schedule straight from a spreadsheet — reference, width, height, quantity — set the design wind pressure, and every pane is checked for bending stress and deflection at once: the thinnest glass that passes, what it weighs, how many people it takes to lift, and the fewest glass make-ups that cover the whole job. Same physics as the single-pane calculator, figure for figure.

The schedule

Reference, width, height, quantity — one pane type per line mm

Paste the columns straight out of Excel, or type them with spaces or commas. A fifth column, if present, is that line's own design pressure — corner and edge zones usually need more. Lines without it use the pressure below. A header row is ignored.

Glass & criteria

Design wind pressure kN/m²

Already factored, from EN 1991-1-4 or ASCE 7. The wind pressure calculator gives you one.

Glass type

Make-up

Thinnest glass you will fit

Thin tempered glass is hard to source and fragile to handle. Set the thinnest your supplier and your practice accept; the check never goes below it.

Deflection limit

EN 16612 sets no deflection limit. It is a project or national requirement — check yours.

Paste a schedule to startOr load the example facade to see what comes out.

Panes

—

Glass area

— m²

all panes

Every pane on four edges, simply supported, under uniform pressure. Same method as the single-pane calculator — the method is below.

Pane by pane

How this is worked out

Each line is checked exactly as the wind-load calculator checks one pane: small-deflection plate theory for a rectangle simply supported on four edges, bending stress σ = β·q·b²/t² against the design strength of the glass type, and centre deflection w = α·q·b⁴/D against the limit you chose, with α and β interpolated from Timoshenko's tables on the aspect ratio. Laminated glass uses the conservative bound — no shear transfer through the interlayer. The two pages share one piece of code, and it is tested against the calculator case by case: they cannot drift apart.

For every line the page walks up the nominal thicknesses — 3, 4, 5, 6, 8, 10, 12, 15, 19 and 25 mm — and keeps the first one that passes both checks. That is the per-pane minimum: the lightest possible job, and usually an impractical one, because a facade of forty panes ends up with five or six different glass make-ups to order, store and fit in the right hole.

Rationalising the make-ups

So the second step asks the question a glazier actually asks: what is the fewest different make-ups that cover every pane, and what does each simplification cost? For one, two, three and four make-ups it finds the combination that adds the least glass weight over the per-pane minimum — every pane goes to the thinnest chosen make-up that still passes. It is an exact search, not a rule of thumb: with ten nominal thicknesses there are never more than a few hundred combinations, and all of them are tried.

The weight assumes 2500 kg/m³ for glass and, for laminated, a 0.76 mm PVB interlayer at 1070 kg/m³ — the same figures as the weight calculator. The crew is the common guideline of about 25 kg per person with suction cups; past four people the page says mechanical lifting instead, because that is what it is.

What this page does not do

Four-edge support only. Two- and three-edge support, point fixings, structural sealant glazing and balustrades are different calculations. Leave those panes out.
Wind only. No snow, self-weight on sloped glazing, barrier loads, impact or thermal stress — a dark tinted pane in sun can crack from heat before the wind ever matters.
Linear theory. Big thin panes deflect past the range where it is accurate; the result is then on the safe side, and those lines are marked.
It does not choose the glass for you. Safety glazing rules, acoustic and thermal requirements, and what your supplier actually stocks all decide the make-up as much as the wind.

Read this. A pre-dimensioning aid for people who already specify glass. It is not a signed structural calculation and does not replace one where your project or code requires it.