(1) Where it is necessary to substantiate any structural design or method of construction, calculations and supporting data, signed by a licensed architect or engineer, shall be submitted to the bureau.

(2) The load bearing capacity of elements or assemblies may be established either by calculations in accordance with generally established principles of engineering design or by tests acceptable to the bureau. When the composition or configuration of elements, assemblies or details of structural members are such that calculations of their safe load-carrying capacity and basic structural integrity cannot be accurately determined in accordance with generally established principles of engineering design, structural properties of such members or assemblies may be established by the results of tests acceptable to the bureau.

(3) All tests shall be performed by a testing agency as defined in ARM 24.301.511 or shall be directed, witnessed and evaluated by an independent licensed architect or engineer. The architect or engineer shall submit his evaluation of test results and recommendations accompanied by test reports from the laboratory to the bureau.