Determine the area to your floating slab and then mark the four corners with 3-feet metal stakes.
Determine the height of the top surface of the concrete slab. Once you've made this determination, use string to mark the height by wrapping it around the metal stakes. Use a level to ensure the string is straight, and the height is consistent.
Measure out two feet in the perimeter (laterally) and mark off this area for drainage.
Measure down 2 feet and 11 inches in the perimeter strings. Here is the starting point of the foundation for the slab. Excavate this entire interior area of the foundation to this depth. Also, excavate the 2-feet drainage section.
Fill the excavated area 3" deep with crushed stone to form a drainage area to the foundation.
Cover the 3 inches of rockfill with 2 feet of sand.
Compact the sand using a tamp (sand compactor) until it is 8 inches below the perimeter lines. Check the area in many locations to make sure the entire area is level.
Place 2"-by-10" (inch) lumber around the perimeter of the proposed slab to create the slab molds. Connect the corners with joints and secure them with framing nails. Make sure the forms are level.
Insert support stakes [2-feet metal stakes with nail holes] each foot along the outside of the slab form. Secure these with framing nails as well.
Remove the initial guideposts and perimeter string. At this point, it's time to install any drainage lines or electrical conduit that must run through the foundation.
Dig a 16-by-18-inch trench just within the slab form to provide extra support on the exterior of the slab to support walls.
Install the 2" (inch) foam insulation over the sand. Cut pieces to fill in the sides and base of this trench as well.
Install a vapor barrier over all of the foam. Overlap pieces by 2" to 4" and secure with tape.
Place the three-eighths-inch rebar at a criss-cross pattern within the vapor barrier. Be sure to use the 2" rebar supports to lift the rebar off the ground so liquid concrete may flow around it.
Add the five-eighths-inch rebar into the trench area. Make a cage formation with the bars to add extra support.Mix and pour your cement. If you're working with a cement delivery service, they will determine the amount of concrete necessary for the pour. Otherwise, you'll have to follow the calculations on your cement bag to determine how much to pour.
The floating slab has the property of spreading the vertical loads or pressures coming over it to be distributed over a larger area.
The floating slab construction can be employed in site areas with lower load-carrying capacity and where investing large money on soil treatment is futile. This system lets us utilize over loose soil or from the soil using varying compressibility.
Some limitations associated with floating slab would be its comparatively primitive technology, entrapped air within sealed floating foundation systems and lower layout resonance.
Floating slab foundations have the distinct disadvantage of lack of underground access for utility lines.
The floating slab construction can be employed in site areas with lower load carrying capacity and where investing large money on soil treatment is futile.
Floating slab have the property of spreading the vertical loads or stresses coming over it to be distributed over a larger area.
Construction: A traditional foundation consists of deep footings, basement walls, and a concrete slab or crawl space.
Footings: Traditional foundations have deep footings that extend below the frost line to provide stability and support for the structure.
Stability: They provide greater stability and resistance to soil movement, settling, and potential damage from moisture.Design Flexibility: Traditional foundations offer more design flexibility, allowing for multiple levels, basements, and crawl spaces.
Soil Assessment: Conduct a thorough soil investigation to determine the soil type, bearing capacity, and potential for settlement. The stability and load-bearing capacity of the soil will affect the design and thickness of the floating slab.
Structural Design: The design of the floating slab should be based on the anticipated loads from the structure it will support. Consider factors such as building dimensions, weight, and any additional loads, such as snow or wind, that need to be accounted for in the design.
Thickness: The thickness of the floating slab should be adequate to distribute the load uniformly and prevent cracking or settlement. It should be determined based on soil conditions, expected loads, and local building codes.
Prepare the area: Clear the site where you want to construct the floating concrete slab. Remove any vegetation, rocks, or debris. Level the ground to ensure a flat and stable base.
Excavation: Dig a trench around the perimeter of the slab area. The depth of the trench should be determined based on the frost line in your region, typically around 6 to 12 inches (15 to 30 cm) deep.
Install formwork: Construct wooden or metal forms to create a framework for the slab. The forms will contain the concrete while it sets. Ensure that the forms are level and securely staked into the ground.
Add a layer of gravel: Place a layer of compacted gravel inside the formwork. This provides a stable base and helps with drainage. The thickness of the gravel layer should be around 4 to 6 inches (10 to 15 cm).
Prepare the area: Clear the garage area and remove any items or obstacles. Make sure the floor is clean and free from debris.
Determine the desired height: Decide on the height of the floating garage floor, taking into consideration any required slopes for drainage and the existing height of the garage entrance.
Install formwork: Construct formwork around the perimeter of the garage floor area. The formwork should be strong and level to hold the concrete in place. Use stakes or other support to secure the formwork.
Excavation (if needed): If the existing garage floor needs to be removed or if you need to create a lower level for the floating floor, excavate the area accordingly. Follow the same steps as mentioned earlier for excavation.
Add a layer of gravel: Place a layer of compacted gravel inside the formwork. This layer serves as a stable base and helps with drainage. The thickness of the gravel layer should be around 4 to 6 inches (10 to 15 cm).