ASTM E1300 12a glass load calculator

What GlassLoad.com checks under E1300 12a

• Thicknesses offered: 2.5, 3, 4, 5, 6, 8, 10, 12, 16, 19, 22 and 25 mm. The calculation uses the minimum thickness of each designation from Table 4, unless you enter a thickness override. There is no 2.0 mm designation in this edition.
• Scope load limit: 315 psf, wind, snow and self weight combined. A design load above it is still checked, with a warning that it is outside the scope of the edition.
• Glass types and durations: annealed, heat strengthened and fully tempered glass, for a short duration load (3 seconds) or a long duration load (30 days).
• Deflection: the approximate center of glass deflection, read from the E1300 deflection chart of the nominal thickness, or from the equation in Appendix X1 where the chart gives no value. Clause X1.1.1 states that deflections larger than the glass thickness are rounded to the nearest millimeter, that a caution applies below one third of the load resistance, and that an aspect ratio above 5 is treated as 5.
• Probability of breakage: E1300 12a has no procedure for it. For annealed glass GlassLoad.com still shows a value, from the glass failure model written in Annex A2 of E1300 24, and the report says so in a warning.

What differs from the other editions

• Against E1300 09a: the scope limit is 315 psf instead of 210 psf, 25 mm glass is offered, the deflection equation is in Appendix X1 instead of Appendix X2, and the three deflection rules of clause X1.1.1 are printed.
• Against E1300 24: there is no 2.0 mm designation, and there is no probability of breakage procedure. The standard describes the probability in lites per 1000, where E1300 24 uses a decimal.
• Examples 9 and 10 of the standard are titled Using Method X2, which is the appendix number of 09a. In 12a, 16 and 24 the equation is in Appendix X1. The label was not updated.

For monolithic glass on four sides, the printed non factored load charts of the editions agree closely. GlassLoad.com therefore uses the same load calculation for all of them, and the edition changes the thicknesses, the scope limit, the appendix names and the warning wording.

25 mm glass

E1300 12a is the first of the editions with a 25 mm designation. The printed chart gives a load about 6 percent lower than the value calculated from the Table 4 minimum thickness of 24.61 mm. GlassLoad.com lets you choose either, and the report says which one it used. E1300 24 prints the same chart.

Run a check with E1300 12a

Open the calculator and pick E1300 12a as the edition. See also the guides, how the calculation works, the questions and answers and the guide on short and long duration glass loads. The other edition pages are E1300 24, E1300 16 and E1300 09a. Results are to be verified by a qualified professional.

Worked examples

These are the worked examples printed in E1300 12a that GlassLoad.com can run. GlassLoad.com computed each one from the printed inputs. Every example has its own page with all the steps. All worked examples

• Example 1, A2.1: Non factored load of a 47.24 by 59.06 in, 1/4 in annealed plate
• Example 2, A2.2: Non factored load of a 50 by 60 in, 1/4 in annealed plate
• Example 3, A2.3: Double glazed unit, 1/4 in tempered over 5/16 in laminated
• Example 4, A2.4: Center of glass deflection, 37.99 by 75.98 in, 1/4 in
• Example 5, A2.5: Center of glass deflection, 60 by 180 in, 3/8 in
• Example 6, A2.6: Triple glazed unit, 1/8, 3/32 and 1/8 in annealed lites
• Example 9, X1.2.1: Deflection with a measured thickness, converted from SI
• Example 10, X1.2.7: Deflection with a measured thickness, inch pound units

Not available in GlassLoad.com

• Example 13, X9.7: Appendix X9 effective thickness of a laminated beam, a laminated cantilever with a line load. Not available in GlassLoad.com.