What can I use for concrete expansion joints?

Asked By: Valeriu Bedding | Last Updated: 3rd May, 2020
Category: business and finance construction industry
4.2/5 (40 Views . 30 Votes)
Concrete Expansion Joints
  • Sikaflex self-leveling sealant.
  • Caulking gun for 29 ounce tubes.
  • Utility knife.
  • Rags (you'll need several)
  • Safety glasses.
  • Nitrile gloves.
  • DeWALT 4 1/2 Inch Angle Grinder.
  • DeWALT Tile Blade for Angle Grinder (this works way better than the blade I used here)

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People also ask, when should you use expansion joints in concrete?

The goal of the control joint is to allow the slab to crack, during expansion and contraction, in a known location and in a straight line. Expansion joints are put in place before the concrete is poured. Expansion joints are used to allow the slab to move and not put stress on whatever it abuts.

Also, should I seal concrete expansion joints? Expansion joints must be sealed with a flexible sealant, like QUIKRETE Self-Leveling Polyurethane Sealant or QUIKRETE Non-Sag Polyurethane Sealant (dependent on application), or an expansion joint strip, to prevent water from penetrating the joint and deteriorating the sub-base.

Just so, how do you clean concrete expansion joints?

Sweep out the expansion joints to ensure that any pebbles, dirt or loose debris are removed. Scrub and clean the surface of the repair area with QUIKRETE Concrete and Asphalt Cleaner and a stiff bristle brush. Thoroughly rinse the area, after cleaning, and wait for the area to dry, before applying any sealant.

Should you fill expansion joints?

Just remember that expansion joints should always be sealed and filled with a flexible joint sealer and never be epoxied or coated over. Contraction joints can be filled in the same manner after a coating or sealer is applied.

18 Related Question Answers Found

How do you fix an expansion joint?

How to Replace Concrete Expansion Joints
  1. Sweep away any dirt and debris from the area.
  2. Dig out and remove all the old material that's in the joints with a putty knife.
  3. With a wet-dry vacuum, clean out the joints between the slabs very well.
  4. Apply a bonding adhesive, usually epoxy, into the joints with a brush.
  5. Insert foam backer rod.
  6. Cover and seal the joint.

How do you fill gaps between concrete slabs?

Scrape off any old patching tar with a stiff putty knife and remove residual tar or asphalt compounds with mineral spirits and gentle scrubbing with a wire brush. Dig a 4-inch wide trench along the sides of the slabs from the crack or gap closest to the house all the way down to the street or sidewalk.

What is the best concrete caulk?

Silicone represents another popular material to use as a concrete caulk. It does not degrade as fast as the organic urethane caulks, and it remains flexible yet sturdy in its hold. One of the best uses for silicone caulk involves filling the gaps between concrete and other materials, such as brick, wood or metal.

How often should expansion joints be used?

How Often Do You Need Expansion Joints? Usually, expansion joints should be no farther apart than 2 to 3 times (in feet) the total width of the concrete (in inches). So for a 4 inch thick concrete slab, expansion joints should be no more than 8 to 12 feet apart.

Where do concrete control joints go?


Space joints (in feet) no more than 2-3 times the slab thickness (in inches). A 4" slab should have joints 8-12 feet apart. Cut joints deep enough. Cut joints 25% of the depth of the slab.

How do you attach concrete to concrete?

A bonding agent (bonding adhesive) needs to be painted onto the existing concrete first to ensure that the fresh concrete will successfully adhere. This is also true of floor repairs, if concrete is used to fill gaps caused by damage. The new won't adhere to the old without the help of a bonding adhesive.

What is the difference between expansion joints and control joints?

A control joint is used to reduce the occurrence of shrinkage in concrete, and it is usually a continuous, vertical joint filled with mortar. An expansion joint is a continuous or horizontal joint.

Does concrete shrink or expand when it dries?

A.: When it first dries, concrete shrinks and undergoes structural alterations that make some of the shrinkage irreversible. Thus, even if it is later resaturated, the initial drying shrinkage isn't fully recovered. However, concrete does indeed expand when it gets hot or when the moisture content changes.

How do you install expansion joints?

INSTALLATION
  1. Apply Lubricant. Rubber expansion joints face flanges may be painted with a solution of graphite in water or glycerin to prevent adherence of joint to pipe flanges.
  2. Insert Expansion Joints into Position. Do not use gaskets for AMS/AMT series.
  3. Insert Bolts.
  4. Tighten Bolts.
  5. Control Rods.
  6. Additional Tips.

Why do they cut lines in concrete?


If you're using concrete to make a sidewalk, the shrinking concrete will cause cracks to appear as it dries. To prevent sidewalks from cracking in random spots and breaking apart, builders make lines in sidewalks. Of course, they don't just call them lines. The technical term for sidewalk lines is contraction joints.

Where are expansion joints used?

Concrete expansion joints are used to separate slabs and concrete from other parts of the structure. Expansion joints allow independent movement between adjoining structural members, minimizing cracking when such movements are restrained.

How do you remove old caulk from concrete?

Clean the edges
First remove the caulk that's in the gap. For latex caulk, pour caulk remover (such as Lift Off; about $6 at home centers and hardware stores) over the caulk, let it sit for two hours, then dig out the caulk with a stiff putty knife. For silicone or polyurethane caulk, use mineral spirits.