Thickness, (1) Concrete slabs shall be not less than 75 mm thick exclusive of concrete topping. [mm]: Inche(s): = Article 9.16.4.3. Ontario Regulation 332/12 Building Code, Information published by oncodes.ca for educational purposes only. Similar articles Concrete in Contact with Sulfate Soil Loads on Guards Table Unit Masonry Columns Materials Maximum number of outlets per circuit (see Appendix B)