Durapanel
Span Calculator

Structural panel allowable spans & post spacing for patio covers — IAPMO UES ER-505 & IAPMO 0195 V3.1.4

IBC 2024 CBC 2025 IRC 2024 ASD Loads Type V-B IAPMO 0195 V3.1.4

A Roof Panel Type

B Projection / Span

Max 23 ft simple span

C Eave Overhang

Max 24 in. per ER-505

D Cover Width

Perpendicular to span

E Live / Snow Load

Selects S8.10.x–S8.50.x automatically

F Wind Speed

G Wind Exposure

Attachment Type

Beam / Header Type

Skin Gauge T(in)

Aluminum skin — S3.1x table

Foam Thickness

Core Density

Fan Beam Insert

Foundation Type

Roof Slope

deg

Min per S3.2 · Max 3°

Multi-Span Panels?

Only 24″ Tri-V Pan qualifies

Ground Snow Load

PSF

Rain-on-snow check (ASCE 7 §7.10)

Tributary Width = Proj ÷ 2 + Overhang

— ft

Quick Summary

—sq ft

—panels

—eave

ER-505 Config Key

—

Panel Span Results — IAPMO UES ER-505

Allowable spans for Durapanel roof panels by load type and pressure

ASD Loads 4 ft Wide Panels Simple Span Only

Enter a Projection / Span value above to see panel span results

Your Span —

Governing Max —

Overall Verdict —

Min Slope —

Span Capacity Matrix — All Load Types & Pressures

■ Pass ■ Fail ■ Not tabulated Each cell shows max allowable span in feet.

Governing Spans by Pressure

Design Notes & Limitations — ER-505

Spans are based on equivalent uniform ASD loads. Consider load combinations and site-specific conditions.
Panel spans assume max temperature differential of 10°F between panel skins (unheated exterior spaces).
Max fastener spacing: 12 in. o.c. Fasteners must be #14 SMS corrosion-resistant with 1-in. neoprene plate washers.
Fastener pull-through capacity: 110 lbf (489 N). Fastener length must be ≥ 1 in. longer than panel thickness.
Panels are 4 ft wide, available up to 24 ft long. Simple-span only — multi-span is outside scope of ER-505.
Max cantilevered eave projection: 24 inches. WUI / Fire Hazard Severity Zones use is outside scope.
Allowable spans for a given thickness are valid for thicker panels of same construction. Extrapolation to longer spans is prohibited.
Construction Type V-B (IBC/CBC). Lateral load-resisting system use is not recognized under this report.

Structural Engineering — Post Spacing & Foundations

IAPMO 0195 V3.1.4 — Sheets S3.1A · S3.1F · S7.1 · S7.2 · S8.xx.y

10–50 PSF LL/SL 110–130 MPH Exp B & C

Adjust inputs above to calculate post spacing, footing size, and minimum post type.

DurapanelSpan Calculator