Building a single-car garage concrete floor requires careful planning, accurate measurements, and the right materials. Here are step-by-step instructions along with the necessary materials and their quantities:

Materials Needed:
– Concrete mix
– Reinforcement mesh or rebar (optional)
– Form boards
– Concrete stakes
– Gravel or crushed stone
– Plastic sheeting
– Concrete sealant (optional)
– Tools: measuring tape, level, shovel, wheelbarrow, hammer, nails, concrete mixer or mixing tools, float or trowel, concrete saw (if needed)

Step 1: Prepare the Site
1. Measure and mark the area where you want to build the garage floor. For a single-car garage, the standard size is usually around 12 feet wide by 20 feet long.
2. Clear the area of any vegetation, rocks, or debris.
3. Excavate the site to a depth of about 6 to 8 inches, ensuring a level base for the concrete. Remove excess soil and create a uniform slope for proper drainage.

Step 2: Install Form Boards
1. Measure and cut the form boards to the desired dimensions of the garage floor. For example, if your garage is 12 feet by 20 feet, you will need four 12-foot boards and four 20-foot boards.
2. Secure the form boards into place using concrete stakes and a hammer. Ensure the boards are level and properly aligned.

Step 3: Prepare the Base
1. Compact the soil at the bottom of the excavation site using a tamper or compactor.
2. Add a layer of gravel or crushed stone to the excavated area to create a stable base. Compact the gravel layer to further enhance stability.

Step 4: Install Reinforcement (Optional)
1. If you want to reinforce the concrete floor, lay down reinforcement mesh or place rebar in a grid pattern across the excavation site.
2. Ensure the reinforcement is raised slightly off the base by using small rocks or wire supports.

Step 5: Pour and Finish the Concrete
1. Calculate the amount of concrete mix needed based on the dimensions of the garage floor. Typically, a 4-inch thick concrete slab is sufficient. Use a concrete calculator to determine the quantity required.
2. Mix the concrete according to the manufacturer’s instructions, either by hand or using a concrete mixer.
3. Pour the concrete into the form boards, starting at one corner and working your way across the entire area.
4. Use a float or trowel to even out the surface of the concrete and remove any air pockets. Ensure the concrete is level and smooth.
5. Allow the concrete to cure according to the manufacturer’s instructions, typically for a minimum of 24 to 48 hours.

Step 6: Finishing Touches
1. Once the concrete has cured, remove the form boards carefully.
2. If desired, apply a concrete sealant to protect the surface from moisture and stains. Follow the manufacturer’s instructions for application.

Building a single-car garage concrete floor requires precise measurements, proper preparation, and the right materials. By following these step-by-step instructions and using the suggested materials, you can create a durable and functional concrete floor for your garage. Remember to consult local building codes and regulations before starting construction, and consider seeking professional assistance if needed.