Homeowner wants a 6-foot slider in an exterior bearing wall of a one-story ranch with trusses.

Header Sizing (No Engineer Needed):

Per IRC Table R502.5(1), for a 6-foot opening in a one-story ranch with trusses (no floor/roof load above the header):

• Header: (2) 2x8s or (2) 2x10s (nominal) with 1/2" plywood spacer between, oriented vertically.
• Span: 6 feet is well within the 2x8 capacity (max 6'-1" for 2x8, 7'-5" for 2x10).

Key Assumptions:

• Trusses are designed to carry loads to exterior walls (standard).
• No second story or heavy roof loads transferred through this wall.
• If trusses bear on this wall, confirm with truss manufacturer that loads are within wall capacity.

Support (Jack/King Studs):

• Use (2) 2x4 jack studs on each end (min).
• (2) 2x4 king studs alongside.
• Footing not required if load transfers through wall to foundation (typical for one-story).

Critical Checks:

1. Verify truss bearing capacity on wall (contact truss manufacturer).
2. Ensure foundation can handle increased point load from header (usually fine for one-story).
3. If snow load >40 psf or roof is low-slope, consult engineer.

Code Reference: IRC R502.5, Table R502.5(1), R802.7 (truss bearing).

If any doubt about truss loads or foundation, call an engineer.

You cannot size this header without an engineer or prescriptive code tables. A 6-ft opening in a bearing wall with trusses exceeds IRC prescriptive limits (Table R602.7(1) max is 4 ft for 2×12 in typical loading). Truss bearing points and point loads from girder trusses often land in these walls—you must verify loads.

*What to gather for the engineer (or to use IRC Table R602.7(1) if loads are standard):*

1. Roof load: Ground snow load (psf), dead load (psf), truss spacing.
2. Wall height: Affects stud capacity and header span.
3. Truss bearing: Does a girder truss or hip girder bear on this wall within 4 ft of the opening? If yes, point load = engineer required.
4. Building width: Determines tributary load width.
5. Header material: LVL, PSL, sawn lumber (species/grade), or built-up 2x.

Support during installation (IRC R602.7, R602.7.5):

1. Temp wall: Build 2×4 wall 12–18″ back from opening, plumb, tight under top plate. Space studs 16″ OC. Critical: Use double top plate on temp wall to distribute load.
2. King studs: Full-height, each side of opening (R602.7.5). Nail to header per Table R602.3(1) (typically 4-16d each end).
3. Jack studs: Two per side minimum for 6-ft span (R602.7.5). Cut precise length—header sits on jacks, not on plate.
4. Header bearing: 3″ min bearing each end (R602.7.1). Use bearing plates if header > wall thickness.
5. Cripples: Above header to top plate, 16″ OC.

Bottom line: If snow load > 30 psf, building > 28 ft wide, or any girder truss bears here—call an engineer. Header will likely be 3.5″×11.875″ or 14″ LVL/PSL.