Repairing and Sealing Cracks in Concrete | Video

  • Transcript

    Over time and exposure to the elements, exterior concrete can develop cracks, due to temperature changes, ground movement, improperly placed joints and excessive loads. Once a crack develops, it is important to seal the crack from water, to prevent further deterioration from water.

    QUIKRETE Polyurethane Concrete Crack Sealant is a non-sag, flexible sealant that will stretch up too 700%, without failing. This allows for ground movement and expansion and contraction from temperature change. Concrete crack sealant’s matte gray color and textured formula is designed too match the surrounding concrete surface, and its non-sag formula can be used on both horizontal and vertical surfaces.

    Concrete crack sealant dries to a permanently flexible, durable material. As with any concrete repair, proper attention to crack preparation is essential to achieving a successful result. Using a chisel and hammer, widen the crack to a minimum of 1/4 inch and break away any deteriorating concrete. The edges of the crack should be vertical or beveled in an inverted V. Then, remove the loose material with a brush.

    For large cracks, over 1/2 inch deep, backer rod, which is a foam rope, should be placed in the crack, before applying the sealant. Always wear eye protection and water-proof gloves, when working with polyurethane sealant, and work in a well-ventilated area. To apply concrete crack sealant, simply cut the nozzle tip at an angle, with a utility knife, to match the width of the crack, and load it into a standard caulk gun.

    Slowly draw the gun down the crack, forcing the bead of concrete repair caulk deep into the crack. When filling the crack, make sure the polyurethane sealant extends, edge-to-edge. Concrete crack sealant can be tooled with a trowel to remove any excess material and to match the surrounding surface, immediately after placement. Concrete crack sealant will be tack-free in about two hours, depending on temperature, humidity and crack depth.

    Excess sealant should be removed, immediately, with a citrus-based cleaner or mineral-spritz and a cloth. Polyurethane sealants are temperature sensitive and should not be used when temperatures are below 50 degrees.

     

    Project Instructions

    When working with cement-based products, always wear eye protection and waterproof gloves. QUIKRETE Concrete Repair, QUIKRETE Gray Concrete Crack Seal or QUIKRETE Self-Leveling Polyurethane Sealant may be used.

    Step 1
    Widen the crack using a chisel and hammer to a minimum of ¼ inch and break away any deteriorating concrete (the edges of the crack should be vertical or beveled in an inverted “v”).

    Step 2
    Remove loose material with a brush.

    Option A: QUIKRETE Concrete Repair

    Step 3a
    Cut the tip of the nozzle on an angle with a utility knife to match the width of the crack and load into a standard caulk gun.

    Step 4a
    Slowly draw the gun down the crack, forcing a bead of Concrete Repair caulk deep into the crack.

    TIP: Concrete Repair can be tooled with a trowel to match the surrounding surface immediately after placement. It will begin to form a skin in about 20 to 40 minutes and will harden completely in 1 to 2 hours.

    Option B: QUIKRETE Gray Concrete Crack Seal

    Step 3b
    Pour the sealant from the bottle, overfilling the crack slightly to allow for settling and shrinkage.

    NOTE: for cracks deeper or wider than ¼ inch, Concrete Crack Seal should be applied in multiple applications, waiting 24 hours between applications.

    Option C: QUIKRETE Self-Leveling Polyurethane Sealant

    Step 3c
    Cut the tip of the nozzle at an angle with a utility knife matching the width of the crack and insert the tube into a standard caulk gun.

    NOTE: for cracks or joints over ¼ inch, a Backer Rod should be placed in the crack before applying the sealant.

    Step 4c
    Move the nozzle slowly along the length of the crack, allowing the sealant to settle.
    TIP: this may require an additional application, which should be done immediately so that the two applications will mend into each other.

    Step 5c
    Excess sealant should be cleaned up immediately with a commercial solvent or a citrus-based cleaner.

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