Bearing Length on a Wood Plate
Required bearing length and actual compression-perpendicular-to-grain stress for a point load on a wood plate.
Example
You enter
- Reaction load (lb) 4000
- Member bearing width (in) 3
- Allowable Fc-perp (psi) 625
- Bearing-area factor Cb 1
You get
- Required bearing length 2.133
- Req area (in²) 6.4
Checked against published worked examples from: NDS compression perpendicular to grain + bearing-area factor.
Details, formula, and sources
ScopeWith a pass/fail against the allowable Fc-perp.
Formula or tableA_req = P / (Fc_perp * Cb); required bearing length = A_req / width; actual f_c_perp = P / (width * provided_length).
Source and editionPer the National Design Specification (NDS) for Wood Construction - compression perpendicular to grain and the bearing-area factor Cb, by name; Fc-perp values user-supplied.
Free accessAWC publishes the NDS free read-only at awc.org; the IBC-adopted edition governs.
What governsEstimate. AHJ and licensed professional govern.
API field namesload_lb, width_in, fc_perp_psi, cb, req_length_in, req_area_in2
- Fc-perp allowable compression perpendicular to grain, user-supplied by species/gradeNDS supplement