SIP Panel

Structural insulated panel (sandwich) — facing, core shear, wrinkling, deflection, axial buckling, bearing.

✓ Validated4 method-verification tests · PDF

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

Panel & Geometry

Panel use Transverse gravity (roof/floor) or axial + out-of-plane wind (wall)

Span / height (ft) Clear span or wall height

Overall thickness T (in) Total panel thickness incl. both facings

Facing thickness t_f (in) Each OSB facing (7/16 in typical)

Loads

Dead load (psf) Roof/floor

Live / snow load (psf) Roof/floor

Out-of-plane wind (psf) Wall

Axial dead (plf) Wall axial

Axial live (plf) Wall axial

Facing & Core Properties

Facing modulus E_f (psi) OSB (verify w/ product ESR)

Allowable facing stress (psi) From the panel's ICC-ES ESR

Core modulus E_c (psi) EPS (representative)

Core shear modulus G_c (psi) EPS (representative)

Allowable core shear (psi) EPS shear, FS applied (ESR)

Allowable bearing (psi) Panel bearing at supports

Design Assumptions

Deflection limit L/

Bearing length (in)

Buckling factor of safety Applied to the shear-reduced critical load (wall)

IBC 2021 / ICC-ES AC04

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

This calculator is verified by 4 method-verification tests comparing its output against the documented design basis and tabulated source values. Full case-by-case results are in the PDF report.

Assumptions

Thin OSB facings act as flanges; EPS core carries shear & stabilises facings.
12-in design strip; simply supported; isotropic linear-elastic materials.
Deflection = bending + shear (shear term significant for SIPs).

Limitations

Facing (OSB) and core (EPS) allowable VALUES are representative — production design must use the panel's ICC-ES ESR (AC04, tested). The sandwich MECHANICS below are independently re-derived; the allowables are not.
No single consensus SIP design code; this tool follows sandwich theory + ESR allowables, not a prescriptive standard.
Splines/panel-joint connections and combined biaxial effects not covered.

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