R311.7.8.5

Section R311.7.8.5 is titled 'Grip size' and covers the requirements for sizing of handrails, providing detailed dimensions for two different types of handrails, but also allowing for other types of equivalent graspability. The purpose of this section is to reduce trip and fall hazards, and prevent cuts.

The model shows 5 different samples of handrails: The first two are Type I with a circular cross section of the minimum and maximum size. (Diameters are labeled). The next two are Type I non-circular cross section, square shaped minimum and maximum size. (Edge length and diagonal are labeled. The diagonal measurement needs to be checked to assure it doesn't exceed the maximum allowed cross section dimension). The last is a Type II with the multiple required dimensions labeled. The edge radius requirement for preventing cuts, does slightly shorten perimeter measurements, but is negligible (about 1/64") and ignored in this model. (Note that the Type I cross section is taken at an angle perpendicular to the longitudinal axis; and the Type II vertical measurements are taken with the longitudinal axis in a horizontal orientation, not a sloped orientation above the stairway.)