(1) Tube and coupler towers used for shoring must have allowable loads based on tests conducted according to the Recommended Procedure for Compression Testing of Scaffolds and Shores, Scaffolding & Shoring Institute, 1967.

(2) Design of shoring layouts must be based on working loads which were obtained using the test procedures of subsection (1) of this section and on at least a two and one-half to one safety factor.

(3) You must inspect all tube and coupler components before being used.

(4) You must not use tubes of shoring structures if heavily rusted, bent, dented, or having other defects.

(5) You must not use couplers (clamps) if deformed, broken, or having defective or missing threads on bolts, or other defects.

(6) The material used for the couplers (clamps) must be of a structural type such as drop-forged steel, malleable iron, or structural grade aluminum. You must not use gray cast iron.

(7) When checking the erected shoring towers with the shoring layout, the spacing between posts must not exceed that shown on the layout, and all interlocking of tubular members and tightness of couplers should be checked.

(8) All baseplates, shore heads, extension devices, or adjustment screws must be in firm contact with the footing sill and the form material, and must be snug against the posts.

(9) Eccentric loads on shore heads and similar members are prohibited unless the shore heads have been designed for such loading.

(10) You must take special precautions when formwork is at angles, or sloping, or when the surface shored from is sloping.

(11) Adjustment screws must not be adjusted to raise formwork after the concrete is in place.