34 Pa. Code § 6.35 – Bracing.

(a) When required. Adequate bracing shall be installed to support walls, arches, piers, columns or any other structural elements; the failure to provide such adequate bracing is a violation of this section and results in a hazard to the safety of workmen engaged in construction, repair or maintenance operations and to other nearby persons.
(b) Approval. All bracing for which specifications are not given in this chapter and all patented or manufactured bracings, parts of braces or bracing devices and all types of braces that are developed shall be of an approved type and it shall be strong and stiff enough to safely perform its function.
(c) Supervision. The erection, alteration, transfer or removal of bracing shall be done under the direction and supervision of men thoroughly experienced in bracing work.
Note: Note: Figure given in column headed ‘‘Strength Rating’’ is the modulus of rupture in bending (pounds per square inch) for sound clear wood with slant of grain not over two degrees.