ASCE 7 ASD Load Combinations: Governing Demand and Net Uplift

Combines dead, live, roof (snow/rain), and signed wind into the seven ASCE 7 §2.4.1 basic ASD combinations and returns the two cases the trades design to: the largest gravity demand (which sizes the beam, joist, or footing) and the most negative case (which, when 0.6D + 0.6W goes below zero, is the net uplift the roof-to-wall hold-down must resist). A member is never designed for one load at a time - the governing combination is, which is why the design starts here, not at the largest single load. A load-combination aid, not a member design.

combos = [D; D+L; D+S; D+0.75L+0.75S; D+0.6W; D+0.75L+0.75(0.6W)+0.75S; 0.6D+0.6W]; governing_gravity = max(combos); controlling_case = min(combos); net_uplift = controlling_case < 0 ? -controlling_case : 0.

ASCE 7 §2.4.1 basic ASD load combinations, by name; the combination coefficients are the standard's values.

The basic ASD load combinations are stated in ASCE 7 §2.4.1; the arithmetic is public.

Estimate. AHJ and licensed professional govern.

Field names used by the API: dead_psf, snow_psf, wind_psf, governing_gravity_psf, controlling_case_psf, net_uplift_psf

• Governing gravity the largest of the seven combinations is the downward demand that sizes the memberASCE 7 §2.4.1
• Net uplift when 0.6D + 0.6W (or another case) goes below zero, the magnitude is the uplift the connection must resistASCE 7 §2.4.1
• Signed wind wind is entered signed: positive downward (pressure), negative upward (uplift)first principles