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Filling Cracks in Cement Walls

Filling Cracks in Cement Walls

Filling Cement Cracks in Your Home’s Walls

When it comes to filling cement cracks, there are certain steps you should take to make sure you won’t have a recurrence. Here’s how you can repair your concrete walls without the help of a professional.

Understanding the Surface

While the terms are often used interchangeably, cement is actually an ingredient of concrete, which consists primarily of gravel, sand, cement and water. As it dries, this slurry cures into a durable slab. Sometimes, however, the curing process can cause cracks due to shrinking. In other instances, structural problems can cause stress cracks, creating entry points for insects, groundwater and dangerous radon gas.

If you have substantial or recurring cracks in your concrete walls, you should contact a professional to determine the underlying cause. If, on the other hand, you’re dealing with minor cracks, you can make repairs yourself using the following steps.

What You’ll Need

  • Caulking gun
  • Margin trowel or wide putty knife.
  • 3-inch finishing nails
  • 2-inch paintbrush
  • Mineral spirits
  • Liquid Concrete Repair Kit containing:
    • Two-part epoxy crack sealer
    • Tubes of LCR (Liquid Concrete Repair)
    • Plastic injection ports

Filling Cement Cracks – The Steps

1.Block out your injection ports.

You can do this by tapping 3-inch finishing nails into the crack, making sure to space each one 12 inches apart. Later, you will use the nails to align your injection ports with the crack.

2. Mix your epoxy.

Open both containers of epoxy sealer and scoop out equal portions of Part A and Part B, making sure to use two different sticks to prevent contamination. Combine Part A and Part B on a piece of scrap wood using a putty knife. Stir the two parts together until the color becomes uniform.

3. Attach your injection port.

Start by spreading some epoxy sealer onto the base of the plastic injection ports, but be very careful not to seal the holes shut. Slide your plastic port over one of the 3-inch finishing nails and press the port firmly against the wall. Repeat this process until you’ve installed all of your ports.

4. Spread sealer over the cracks.

Begin by mixing together a larger batch of epoxy sealer and spread the mixture over the entire crack using a margin trowel or wide putty knife. Spread the epoxy approximately one-eighth of an inch in thickness and fan it out about an inch to both sides of the crack. You should also cover the whole flange of every injection port with epoxy, so only the neck shows. Smooth the epoxy and blend in the edges by feathering with a paint brush dampened with mineral spirits. Allow the epoxy to cure for six to ten hours before proceeding.

5. Inject epoxy into your ports.

Mix the LCR epoxy and place the cartridge into your caulking gun. Begin at the lowest port and dispense your sealer into the crack. Continue dispensing until you see sealer start to ooze from the port. Once you’ve filled the crack, you should plug up the port: Insert the tip of your LCR cartridge into each port and dispense sealer to plug them up.

6. Cut off your injection ports.

Be sure to let the LCR cure for at least five days. Then, use a box blade or hacksaw to neatly slice off the necks. If you are unsatisfied with the aesthetics, you can use a small amount of crack sealer to patch the severed ports.

Things to Consider

If you can see the other side of the cement wall, look it over to see if the crack goes all the way through. If it does, seal that side the same way.

You should also consider the cause of your cracks before you begin making repairs. Because they are often caused by foundation problems, cracked concrete walls can be a sign of major structural issues. If you have a 10-year structural warranty, you may be able to sidestep costly repairs. If not, you could end up paying tens of thousands of dollars to fix the problem. Whatever the case, never ignore signs of structural distress, or your small defect could evolve into a catastrophic repair bill. If you notice substantial or recurring cracks, don’t attempt to fix them yourself. Instead call a structural engineer for an in-depth evaluation.

2-10 HBW offers the most comprehensive Home Warranty coverage for homeowners. Let us help you protect your home.