How to Finish Concrete: Tools and Techniques

Learn concrete finishing techniques: screeding, floating, troweling, and edging for professional results.

Proper finishing transforms poured concrete into a durable, attractive surface. Each step serves a specific purpose and must be done at the right time.

Finishing Tools Needed

Screed board: 2x4 or magnesium screed, longer than slab width
Bull float: Large float for initial smoothing (wood or magnesium)
Hand float: Smaller float for detail work
Edger: Creates rounded edges along slab perimeter
Groover: Creates control joints in the surface
Trowel: Steel or magnesium for final finish
Broom: For creating non-slip texture

Step 1: Screeding

Begin immediately after pour, while concrete is fluid
Use sawing motion with screed board
Work from one side to opposite side
Fill low spots and re-screed high spots
Don't overwork - brings cement to surface (bad)
Goal: Level surface, remove excess concrete

Step 2: Bull Floating

Wait until bleed water sheen disappears
Float in large arcs, lifting leading edge slightly
Don't seal surface - water needs to escape
Embeds aggregate and closes surface imperfections
Magnesium floats: Faster, lighter, for air-entrained concrete
Wood floats: Slower, more workable, closes surface more

Step 3: Edging and Grooving

Run edger along forms after bull floating
Creates rounded, less likely-to-chip edge
Cut control joints with groover at marked locations
Joints should be 1/4 to 1/3 of slab depth
Space joints 2-3 times slab thickness (in feet)

Step 4: Floating (Second Pass)

Wait until concrete can support foot traffic (slight imprint)
Use hand float or power float for large areas
Remove imperfections from edging and grooving
Further close surface and prepare for troweling

Step 5: Troweling

Wait until concrete is firmer (harder footprint)
Steel trowel: Smooth, hard, slick finish
Magnesium trowel: Less smooth, faster application
Multiple passes: Increasing pressure and decreasing angle
Final trowel creates very smooth, hard surface

Step 6: Broom Finish (Optional)

For exterior slabs requiring traction
Drag broom lightly across surface after final trowel
Consistent pressure and direction for uniform texture
Coarse broom: Rougher texture (driveways)
Fine broom: Lighter texture (patios)

Pro Tips

Wait for bleed water to disappear before floating - critical timing
Over-troweling creates weak surface layer (dusting)
Keep tools clean - hardened concrete ruins them
Work in cool weather extends workable time significantly
Power trowels require experience - hand trowel for beginners

Important Warnings

Working bleed water back into surface weakens concrete
Troweling too early seals surface, causing blistering and scaling
Smooth exterior finishes are slippery when wet - add texture
Power tools can dig into concrete - proper technique essential