CBC handrails must be “graspable” by meeting either Type I or Type II profile criteria. Type I circular rails must be 1-1/4 in. to 2 in. outside diameter; noncircular rails must have a perimeter of 4 in. to 6-1/4 in., a maximum cross-section of 2-1/4 in., and a minimum cross-section of 1 in.; edges require a minimum 0.01 in. radius. Type II rails (perimeter > 6-1/4 in.) must have finger recesses on both sides beginning within 3/4 in. of the top, reaching at least 5/16 in. depth within 7/8 in. below the widest point, continuing at least 3/8 in. to a level not less than 1-3/4 in. below the top; the width above the recess must be 1-1/4 in. to 2-3/4 in.; edges require a 0.01 in. minimum radius. Equivalent graspability is permitted. See § 1014.4, § 1014.4.1, and § 1014.4.2.
Type I profiles (most common)
- Circular: outside diameter 1-1/4 in. to 2 in. (§ 1014.4.1).
- Noncircular: perimeter 4 in. to 6-1/4 in.; max cross-section 2-1/4 in.; min cross-section 1 in.; edges ≥ 0.01 in. radius (§ 1014.4.1).
Type II profiles (larger rails)
- Required when perimeter > 6-1/4 in. (§ 1014.4.2).
- Finger recess on both sides:
- Start within 3/4 in. vertically of the top;
- Reach ≥ 5/16 in. depth within 7/8 in. below widest portion;
- Continue ≥ 3/8 in. to a level ≥ 1-3/4 in. below top;
- Width above recess: 1-1/4 in. to 2-3/4 in.;
- Edges ≥ 0.01 in. radius (§ 1014.4.2).
Gripping surface and obstructions (accessibility)
- In areas covered by Chapter 11B, gripping surfaces must be continuous, not obstructed along tops or sides; bottoms may not be obstructed for more than 20% of their length. Horizontal projections must occur 1-1/2 in. minimum below the bottom of the gripping surface, with a small allowance to reduce that distance as rail perimeter increases (§ 11B-505.6).
- Cross-section ranges in 11B mirror the Type I envelope: circular 1-1/4 in. to 2 in. diameter; noncircular perimeter 4 in. to 6-1/4 in., max cross-section 2-1/4 in. (§ 11B-505.7.1, § 11B-505.7.2).
- Surfaces must be free of sharp or abrasive elements and have rounded edges (§ 11B-505.8).
Note: § 1014.4 applies to required handrails generally, and it explicitly permits Type I or Type II (or equivalent) in Group R-3 dwellings, certain Group R-2 dwelling units, and accessory Group U spaces (§ 1014.4 Exception).