Division B
Acceptable Solutions

Part 9 — Housing and Small Buildings

Section 9.16. Floors-on-Ground

9.16.1. Scope Application
1) Intent StatementThis Section applies to floors supported on ground or on granular fill that do not provide structural support for the superstructure. Structural Floors
1) Intent StatementFloors-on-ground that support loads from the superstructure shall be designed in conformance with Part 4. Required Floors-on-Ground
1) Intent StatementAll spaces within dwelling units, except crawl spaces, shall be provided with a floor-on-ground, where
a) access is provided to the space, and
b) a floor supported by the structure is not provided. Dampproofing and Waterproofing
1) Intent StatementDampproofing and waterproofing shall conform to Section 9.13.

9.16.2. Material beneath Floors change beginRequired Installation of Material Beneath Floors-on-Ground
1) Intent StatementExcept as provided in Sentence (2), a drainage layer shall be installed below floors-on-ground. (See Appendix A.)
2) Intent StatementThe drainage layer required in Sentence (1) need not be installed below
a) slabs in garages, carports or accessory buildings, or
b) buildings of industrial occupancy where the nature of the process contained therein permits or requires the use of large openings in the building envelope even during the winter.change end

contentHistory Support of Floors
1) Intent StatementMaterial that is susceptible to changes in volume due to variations in moisture content or chemical-microbiological oxidation shall not be used as fill beneath floors-on-ground in a concentration that will damage the building to a degree that would adversely affect its stability or the performance of assemblies. (See also Article and A- in Appendix A.)
2) Intent StatementMaterial that is susceptible to changes in volume due to freezing shall not be used as fill beneath floors-on-ground that will be subjected to freezing temperatures. (See also Article and A- in Appendix A.)
3) Intent StatementExcept as provided in Sentence (4), fill beneath floors-on-ground shall be compacted.
4) Fill beneath floors-on-ground need not be compacted where the material is change begincoarse clean granular materialchange end containing not more than 10% of material that will pass a 4 mm sieve.


9.16.3. Drainage Control of Water Ingress
1) Intent StatementExcept as provided in Article or where it can be shown to be unnecessary, ingress of water underneath a floor-on-ground shall be prevented by grading or drainage. Hydrostatic Pressure
1) Intent StatementWhere groundwater levels may cause hydrostatic pressure beneath a floor-on-ground, the floor-on-ground shall be
a) a poured concrete slab, and
b) designed to resist such pressures. Floor Drains
1) Intent StatementWhen floor drains are required (see Section 9.31.), the floor surface shall be sloped so that no water can accumulate.

9.16.4. Concrete Surface Finish
1) Intent StatementThe finished surface of concrete floor slabs shall be trowelled smooth and even.
2) Intent StatementDry cement shall not be added to the floor surfaces to absorb surplus water. Topping Course
1) Intent StatementWhen a topping course is provided for a concrete floor slab, it shall consist of 1 part cement to 2.5 parts clean, well graded sand by volume, with a water/cement ratio approximately equal to that of the base slab.
2) Intent StatementWhen concrete topping is provided, it shall not be less than 20 mm thick. Thickness
1) Intent StatementConcrete slabs shall not be less than 75 mm thick exclusive of concrete topping. Bond Break
1) Intent StatementA bond-breaking material shall be placed between the slab and footings or rock.

9.16.5. Wood Wood-Frame Floors
1) Intent StatementFloors-on-ground constructed of wood shall conform to CAN/CSA-S406, “Construction of Preserved Wood Foundations.”