Concrete Finishing - How To Tips for Slabs

Concrete finishing is easier with a crew that can work as a team. Decorative Concrete Institute in Temple, GA

Concrete finishing is a process that strives to create a smooth, durable surface. When finishing concrete, timing is crucial and you must pay close attention to the condition of the concrete. Improper finishing techniques can lead to a weak, damaged or unattractive slab.

CONCRETE FINISHING TOOLS

Once you’ve formed and poured the concrete you’re ready to start the finishing process.

Here are the tools you will need for this job:

• Square shovel or come-along
• Screed or straight board
• Bull float or darby
• Edging tool
• Concrete groover
• Steel trowel or fresno

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HOW TO FINISH CONCRETE

Once you have your tools, you're ready to get started. Here are the steps for finishing a concrete slab:

1. Spread the concrete

   Use a square shovel or a come-along tool to push and pull the wet concrete into place.

2. Screed the concrete

   During this step remove excess concrete and bring the surface of the concrete to proper grade. Use a straight board or special tool called a screed.

3. Float the surface

   Use a darby or bull float to level ridges, fill voids and slightly embed the aggregate. Then allow the bleed water to disappear.

4. Edge the slab

   Once all the bleed water is gone, create neat rounded edges along the perimeter of the slab using an edger.

5. Groove in joints

   Prevent unwanted cracks by jointing the slab with a grooving tool.

6. Trowel the surface

   If you’re looking for a smooth, hard, dense surface, use a steel trowel or fresno for this step. Skip troweling if you plan to broom finish your concrete or add a decorative finish.

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CURE AND SEAL THE CONCRETE

Once you’re done with finishing, let the concrete dry and achieve full strength, this is called curing. You can use your concrete for light foot traffic 3 to 4 days after placement, and you can drive and park on your concrete after 5 to 7 days, but curing isn’t complete until the 28 day mark. Once the concrete is fully cured, apply a protective sealer to prevent stains and prolong the life of your slab.

CONCRETE FINISHING TIPS AND TRICKS

A good finisher is produced through training and years of experience. Books have been written about this topic, and only experience provides the ability to expertly "time" the finishing operations.

To give you a head start, here are finishing tips from the pros:

• Place the concrete as close as possible to its final destination (concrete weighs approximately 150 pounds per cubic foot).
• Excess handling can cause segregation of the course and fine aggregates.
• Wetting up the concrete so it can be raked or pushed into a location far from where it is discharged is not acceptable.
• Do not use a round edge shovel for spreading concrete since it does not spread the concrete evenly.
• "Strikeoff" or screed the concrete as close as possible to its final plane.
• Don't tamp high slump concrete.
• Bull floating should be finished before excess moisture or bleedwater appears. When floating, lift the leading edge slightly off the concrete surface.
• Don't fresno the slab right after screeding - bleedwater and air trapped beneath the sealed surface will create blisters that later break or a weakened plane that causes sheet delamination.
• Dont finish the concrete while there is bleedwater on the surface. Using a finishing tool while there is water on the surface increase water-cement ratio by working the water back into the concrete instead of letting it evaporate. This can cause dusting, scaling and craze cracking.

Read other tips on Building a High Quality Slab on Grade.