SIP Header / Lintel

Panel self-header (box beam) over openings; sizes an inserted lumber/LVL header when the panel can't span.

Facing, core and allowable-shear values are product-specific — substitute the values from the panel's ICC-ES ESR (AC04). The defaults are representative only and must not be used for final design.

Design diagram — updates live with your inputs

Opening & Panel

Opening width (clear) (ft)

Panel thickness T (in)

Facing thickness t_f (in) Each OSB facing

Panel depth above opening (in) Height of SIP strip available to act as a beam (h_b)

Loads

Tributary width (ft) Load width carried to the header

Dead load (psf)

Live load (psf)

Snow load (psf)

Point dead (mid-span) (lb) Optional

Point live (mid-span) (lb) Optional

Facing Properties (ESR)

Facing modulus E_f (psi) OSB (product ESR)

Allowable facing bending (psi) Product ESR

Allowable facing shear (psi) OSB in-plane shear (product ESR)

Inserted Header & Limits

Inserted header F_b (psi) LVL default; DF No.2 ~900

Inserted header E (psi) LVL default

Inserted header F_v (psi) LVL default

Inserted header width (in) Beam width b (e.g. 3.5 in = two 2x or 3.5 LVL)

Deflection limit L/

Bearing length (in)

Allowable bearing (psi) Bearing at header ends

IBC 2021 / ICC-ES AC04

Validation, assumptions & limitations Download validation report (PDF) ↗

This calculator is verified by 4 independent tests comparing its output against closed-form statics, NDS/SDPWS design-standard values and published worked examples. Full case-by-case results are in the PDF report.

Assumptions

Tributary gravity load delivered uniformly to the header over the opening; simple-span.
Box beam = two OSB facings as webs of depth h_b; core/spline ignored (conservative).
Inserted header is a solid rectangular section of the input width.

Limitations

Facing E and allowable bending/shear are PRODUCT-SPECIFIC (ESR / AC04).
End splines and edge lumber that add capacity are neglected.
Inserted-header sizing reports a required depth and a nominal pick; confirm the actual member's NDS-adjusted capacity.

Results are for preliminary design and must be confirmed by a licensed engineer against the current adopted code and project-specific conditions.