The installation of all piling shall be subject to controlled inspection. Such inspection shall be performed only by an architect or engineer resident at the site, except that where more than one pile rig is working at a site, inspection of the work may be performed by nonlicensed or nonregistered personnel working under the resident architect or engineer, who need act only in a supervisory capacity. This exception shall not apply, however, in the cases of timber or steel piles driven to end bearing as described in article ten of this subchapter. Materials for piling shall be subject to inspection requirements as prescribed in subchapter ten of this chapter for those or like materials. In all cases, an inspector shall be assigned to observe the operations of each rig.