a "Slab on Grade" (SOG) refers to a type of foundation that consists of a concrete slab poured directly on the ground. This method is commonly used for its simplicity and cost-effectiveness. The slab serves as both the foundation and the ground floor of the building.
Here are some key characteristics and considerations for SOG in Australian commercial construction:
Site Preparation: The ground must be properly prepared, which includes clearing vegetation, leveling, and compacting the soil to provide a stable base for the slab.
Sub-base: A layer of gravel or crushed stone is often placed beneath the slab to improve drainage and prevent moisture from seeping into the concrete.
Moisture Barrier: A plastic or polythene sheet is typically laid over the sub-base to act as a moisture barrier, preventing ground moisture from penetrating the slab.
Reinforcement: Steel reinforcing bars (rebar) or mesh are embedded within the concrete to provide tensile strength and reduce the risk of cracking.
Concrete Pouring: The concrete is poured and spread evenly across the prepared area. It is then leveled and smoothed using various tools.
Curing: Proper curing of the concrete is essential to achieve the desired strength and durability. This involves maintaining adequate moisture and temperature conditions for a specified period.
Expansion Joints: These are incorporated to accommodate any movement due to temperature changes or settling, helping to prevent cracking.
Insulation: In some cases, insulation may be added to improve energy efficiency, particularly in climates with extreme temperatures.
Slab on grade foundations are suitable for flat or gently sloping sites and are commonly used in commercial buildings like warehouses, retail spaces, and industrial facilities. They provide a durable and low-maintenance flooring option, though they may not be ideal for areas with poor soil conditions or significant frost heave.
