Planning & Preparation
To calculate square footage multiply Length times Width in feet.
Length X Width = Square Feet
Below is a reference list of coverage for different thicknesses.
3” = 106 sq ft
3.5” = 93 sq ft
4” = 81 sq ft
4.5” = 72 sq ft
5” = 65 sq ft
5.5” = 59 sq ft
6' = 54 sq ft
If your dimensions do not fit these guidelines, you can figure most anything that has all flat sides with the following formula:
Length X Width X Depth, divided by 27 = cubic yards.
The values must all be in feet.
To convert inches to feet simply divide the number of inches by 12. For example: 4 inches divided by 12 is .33 feet. 6 inches divided by 12 is .5 feet.
Placing & Finishing
Most surfaces will require strike-off or screeding to proper contour and elevation. In this process a straight edge (2X4 on edge) is moved across the concrete with a sawing motion.
Bull-floating eliminates high and low spots and embeds large aggregate particles immediately after strike-off. Jointing is required to eliminate unsightly random cracks.
1. Can be made with a hand groover while the concrete is wet enough to work. The grooves should be at least 1\2 inch to 3\4 inches deep.
2. This can also be done by inserting strips of plastic, wood, metal, or preformed joint material into the unhardened concrete though this process is much harder to get right.
3. Another method of making relief joints and a bit cleaner look is to saw-cut joints after the concrete is hard enough to prevent chunking along the cut line.
After the concrete has been jointed, it should be floated with a wood or magnesium float or with a finishing machine using float blades. This embeds aggregate particles just beneath the surface; removes slight imperfections, humps, and voids; and produces the grout layer at the surface in preparation for additional finishing. Where a smooth surface is desired, floating should be followed a short time later with steel troweling. A slip-resistant surface can be produced by brooming before the concrete has completely hardened, but it should be sufficiently hard to retain the scoring impression from the bristles. If the surface grout moves in front of the broom, it is too soon.