Concrete Repair Tips

Repairing Hairline Cracks In Concrete

• You can repair hairline cracks in concrete with a grout made of Portland cement and water. Add just enough water to the cement to form a thick paste.
  
  
• Moisten the old concrete along the hairline crack with water for several hours before adding the grout. Moistening the concrete prevents it from drawing the water from the grout, which will dry out the mixture. Although the old concrete should be moist, no water should be standing on the surface when the grout is applied.
  
  
• After the hairline crack has been moistened and thoroughly cleaned, apply the grout with a putty knife or pointing trowel. Force the grout into the crack as much as possible. Then smooth it off so it is level with the original concrete.
  
  
• Allow the patched area to dry about two hours. Then, cover the area with a piece of plastic sheeting or a board.
  
  
• Keep the area covered for about five days. Lift the covering once each day and sprinkle the area with water.