Par. 1. - Permits. - Before a permit is granted to erect any building except temporary buildings or buildings of minor importance, the commissioner may demand such further drawings, strain sheets, and description as will clearly show the entire construction, assumptions, calculations of stresses and all other structural details. Such details shall be in the form required by the commissioner, and calculation sheets shall be signed by the architect, engineer, contractor or other person responsible for them.

Par. 1. a. - The commissioner shall not delay the issuance of a building permit if the plans submitted conform to the laws as to egress, class of construction and general arrangements, provided that the plans are accompanied by drawings showing the structural design and by a statement that the plans and designs conform to all the requirements of the law as to strength, stresses, strains, loads and stability and are signed and sworn to by the architect or engineer who made the calculations. The commissioner may examine, or cause to be examined, the structural design submitted, and may require such changes in size or material as may be necessary to comply fully with the requirements of this act.

Par. 1. b. - Permits for general repairs, for minor alterations not involving extensive structural changes, and for small buildings of the second or third class, may be issued upon presentation of the application on a special blank for the purpose.

Par. 2. - Systems not Covered by this Act. - If an applicant for a permit to build desires to use as a substitute for the materials or methods covered by this act materials or methods of construction or maintenance not covered by it, he shall present to the commissioner plans, formulas, and such other information, and shall make such tests or present satisfactory evidence of such tests, as the commissioner may require. Such systems shall not be used until after the commissioner has issued general regulations fixing the methods to be followed, but no such regulation shall have the effect of altering the working stresses for any material herein mentioned or of reducing the fireproofing requirements of this act.

Par. 3. - It shall be the duty of the board of appeal to submit to the mayor on or before the first day of February in each year a report giving a summary of all decisions of the board, together with such recommendations for revision of the law as the board may deem advisable. The commissioner shall cause the report to be printed as a separate document for public distribution.

Par. 4. - Any requirement necessary for the strength or stability of any proposed structure or for the safety of the occupants thereof, not specifically covered by this act, shall be determined by the commissioner, subject to appeal.

Par. 5. - Testing. - ■ The commissioner may order loading tests to be made, at the expense of the owner, on any structure or part thereof, at such time and in such manner as will satisfactorily demonstrate to him that the unit stresses in any materials do not exceed those permitted under this act. Concrete construction shall be capable of bearing a live and dead load equivalent to twice that for which it was designed without causing permanent deformation.

Par. 6. - No such test on the structure shall be required, however, until notice thereof in writing has been given by the commissioner to the person to whom the building permit was issued.

Par. 7. - Load Test. - When the strength of any floor construction cannot be determined by the methods prescribed in this section or by the application of accepted engineering formulas, the safe uniformly distributed carrying capacity shall be taken as one sixth of the total load causing failure to a full-sized construction with the load applied at two points, each at one third of the span from the ends of the span.

Par. 8. - Fire Tests. - In testing the fireproof qualities of any floor construction, at least one panel of the proposed maximum span, carrying a live load of at least one hundred and fifty pounds per square foot, shall be subjected to a fire continuously for four hours at an average temperature of seventeen hundred degrees Fahrenheit, followed by an application for at least ten minutes of a hose stream from a one and one eighth inch nozzle at sixty pounds nozzle pressure, without appreciable deterioration or the passage of flame through the floor during the test.

[1918, c. 179, sect. 1, Special Act.] [1920, c. 266, sect. 1.]