Header sizing: span = rough opening; double 2x members typical
HUD RSDG §5.5.3Description
Load-bearing headers carry loads from walls / ceilings / floors / roofs above and transfer them to jack + king studs each side of the opening. Header span = the rough opening width measured between the jack studs. Typical residential headers are built up from two nominal 2-inch members (e.g. double 2x10 for a 6-ft opening under one story). Use engineered wood, hot-rolled steel, or flitch-plate beams for spans > 10 ft or under heavy loads.
Why this exists
Header is the most-frequently-designed structural element in residential framing. Deflection at L/240 for a 10-ft opening = 0.5 in — enough to bind windows and doors above. Architects must size with the expected load (1 story vs 2 stories above) + the opening span, not just by tradition.
Measurements
| Property | Operator | Value | Unit | Note |
|---|---|---|---|---|
typicalDoubleMemberLimit | max | 10 | ft | Span above which engineered headers are recommended |
bindingDeflection | max | 0.5 | in | Deflection at 10-ft span that begins to bind windows/doors |
Categories
Source
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Related directives
- Continuous load path from roof to foundation · HUD RSDG §2.4
- Residential structural reliability targets 1-in-100 to 1-in-1000 annual probability of failure · HUD RSDG §2.5
- Residential floor live load: 40 psf minimum (30 psf sleeping rooms) · HUD RSDG §3.4
- Wind load design uses ASCE 7 basic wind speed for the locality · HUD RSDG §3.6
- Ground snow load for Virginia: 25 psf eastern, up to 40 psf western mountains · HUD RSDG §3.7
Last reviewed 2026-05-14.