Guard and Handrail Code Check
Whether a guard and handrail meet the dimensional code.
Example
You enter
- Occupancy residential
- Walking-surface height above below (in) 48
- Measured guard height (in) 36
- Largest infill / baluster gap (in) 3.5
- On a stair? no
- Measured handrail height (in, stairs) 36
You get
- Guard required Yes
- Guard height ok (min 36 in)
- Infill gap ok (max 4.000 in)
- Guard ok Yes
- Infill ok Yes
- Verdict all checks pass
Checked against published worked examples from: American Wood Council.
Details, formula, and sources
Scopea guard is required where the walking surface is over 30 in above the floor below, with a 36 in (residential; 34 in on a stair) or 42 in (commercial) minimum height, a 4 in sphere infill limit (4-3/8 in on a residential stair), and a 34-38 in stair handrail. IRC R321 [R312 in IRC 2021] / R318.7.8 [R311.7.8 in IRC 2021] / IBC 1015; the assembly must also carry a 200 lb load and the AHJ governs.
Formula or tableguard required where surface_height > 30 in; min guard 36 in residential (34 in on a stair) / 42 in commercial; max infill 4.0 in (4.375 in on a residential stair); stair handrail 34-38 in. Each measured value is compared to its limit; a 200 lb concentrated load applies regardless.
Source and editionIRC 2024 (International Residential Code) Section R321 [R312 in IRC 2021] (guards) / R318.7.8 [R311.7.8 in IRC 2021] (handrails) and IBC 2027 Section 1015 (42 in guard and 4 in sphere unchanged from 2021) by section; dimensional minimums only, not reproduced.
Free accessRead-only at codes.iccsafe.org. The dimensional minimums are facts; the AHJ-adopted code and edition govern.
What governsEstimate. AHJ and licensed structural engineer govern.
API field namesoccupancy, surface_height_in, measured_guard_in, measured_infill_gap_in, at_stairs, measured_handrail_in, guard_required, min_guard, max_infill, guard_ok, infill_ok, all_pass
- Thresholds guard over 30 in surface; 36 in residential (34 in on a stair) / 42 in commercial height; 4 in sphere infill (4-3/8 in on a residential stair); 34-38 in handrailIRC R321 [R312 in IRC 2021] / R318.7.8 [R311.7.8 in IRC 2021] / IBC 1015
- Load guards and handrails must also resist a 200 lb concentrated load in any direction (IRC R301.5 / IBC 1607); this tool checks dimensions onlyIRC R301.5
- AHJ governs the AHJ-adopted code and edition govern the final acceptanceAHJ