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Grout Cracking After Drying – What To Do?

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Applying grout around the tiles is an important thing to do in any tiling project, that's why it's annoying to find it damaged with cracks after leaving it to dry. But don't worry! We have researched and prepared all the essential information you'll need if you find your grout cracked after drying.

If you find your grout cracked after leaving it to dry, thoroughly remove the grout from the joints and reapply a new layer of grout. Do not apply more to cover cracked and crumbling grout because it will not provide a stable surface for the new layer to bond to. You can use caulk or polymeric grout to avoid more cracking in the future.

While cracked grout might feel like it requires a lot of time and energy to save, you don't need to restart the project. With a little effort, you can save your work and keep up with your project's schedule. Continue reading as we discuss the important details you need to repair a cracked grout.

A man spreads wet cement on a cracked sidewalk, Grout Cracking After Drying - What To Do?

How Do I Fix A Cracked Grout?

If you find that the grout you applied has formed cracks, the right thing to do is to remove the damaged substance and replace it. A common reason for cracked grout is too much water was mixed in the substance, thus producing a blend that is too weak to set.

It's not advisable to simply cover the cracks with more grout. This practice would only cover the crack, but would not repair the damage. Remove the old grout and reapply a new one. This way, you can preserve the design you have made, especially if you are working with something that has intricate details like a mosaic backsplash.

old stained grey concrete wall texture

How To Apply Caulk

Caulk has the same function as a grout, as both of them are used to fill in gaps. However, caulk is arguably a better material for areas where small movements might occur, like a piece of wooden furniture expanding, or tiles growing in size due to water absorbency. Below are the steps you can follow to apply the caulk properly.

  1. Locate the damaged area and remove the grout.
  2. Dust off the grout rubble and thoroughly vacuum the remaining debris off the workspace.
  3. Cut off a hole on the tip of the caulk cartridge with a size that matches the grout joint. Make sure to cut it at an angle for easier application.
  4. After securing the cartridge on the caulk gun, carefully squeeze the trigger of the tool at a 45-degree angle and place it over the grout joint.
  5. Slowly pull away as you create a line of caulk on the joint evenly, without pushing the material and creating bumps and ridges.
  6. Once the gaps are filled, smooth them over with a plastic spoon, or a caulk finishing tool in order to clean the application.
  7. Slightly push the smoothing tool over the caulk to make sure that the material has completely filled in all the small crevices in the joint.
  8. Clean up any excess caulk with a damp sponge or cheesecloth.
  9. Let the caulk set for at least 48 hours.

How To Apply Polymeric Grout

Polymeric grout is low density with a cement base and polymer additives which makes this mixture good when preserving its color. This type of grout becomes liquid and abrasion resistant when mixed with water.

Polymeric grout is best to use on areas that are mostly exposed to water such as a kitchen backsplash, fountains, or shower area. Below is a simple step-by-step guide that can help you apply polymeric gout properly.

  1. Thoroughly clean the surface of the tiles and around the joints where you will apply the grout. (For natural stone installations, makes sure that the tiles are sealed before applying anything on it.)
  2. With a grout trowel, pick up a small amount of the mixture.
  3. Carefully spread the polymer grout around the tiles, putting extra care to fill in the space inside the joints. Make sure that you are moving the spreading tool in one direction along the grout lines in order to accomplish a clean finish.
  4. Before washing off the excess grout, wait at least ten minutes for the mixture to set.
  5. Let the polymer grout rest for at least 24 hours.

Why Is My Newly Installed Grout Cracking?

The most common reason for cracked grout relates to the amount of water that you added in the mixture. If the ratio of cement to water is off, then the grout will shrink once the water has evaporated during the drying time.

When doing a home project without prior knowledge of grout application, make sure to carefully read and follow the instructions that came with purchasing the grout. This will ensure that the grout you will use is prepared properly and you won't end up with a grout that won't set well.

Crack on cement wall bare polished grey color and smooth surface texture

External Factors That Can Affect The Grout

Another reason could be that there was a deflection on the substrate where you placed your tiles. This means that the area where you installed your tiles was not stable enough to hold them into place, causing them to move and in turn, creating cracks and crevices on your newly applied grout.

By evaluating the area you are working on, it'll be easier for you to make the right decision when it comes to what grout is appropriate for the project. For example, a tiled kitchen floor can benefit from a cement-based grout, but a backsplash with wooden cupboards can use a flexible filler, expecting the slight expansion of the wood that can cause cracks on grout.

How Do I Prevent Grout From Cracking?

The hand of man holding a rubber float and filling joints with group

Cracked grout can cost you more than you initially planned for a tiling project, especially if you used the same mixture for a whole area without conducting a trial on a smaller surface first. In order to avoid more cracking grout in the future, it's best to understand how the mixture works. Below is a list of helpful tips to help you prevent your grout from cracking again.

  1. Do not use a heater to dry your grout faster. This will affect the water in the mixture which will shrink the grout, making it susceptible to cracks.
  2. If your grout mixture in the bucket appeared to have solidified while you were applying it to the joints, simply mix it again to reactivate. Avoid adding more water into the mix.
  3. Make sure that you apply gentle pressure when going over the gaps to ensure that the filler is penetrating all the spaces and small crevices between tiles.
  4. Do not clean the grout immediately after application. Wait for it to set before using a damp item to clean it.
  5. Moisten the grout joint if you know that the tile you chose is dry and absorbent. This will ensure that your filler will set well without the tiles absorbing the water in the mixture.
  6. Make an effort to regulate the temperature of your workplace so that materials such as wood and metal would not create movement in the substrate substantial enough to cause cracks in the grout.

Wipe the tiles with a finishing grout

What Type Of Grout Should I Use?

Sanded and unsanded grout are the two main types of filler in the market. For tiling projects with grout joints measuring 1/8" to 1/2" wide, sanded grout is recommended. Sanded grout is also less expensive, which makes it preferable to use on bigger projects like a kitchen. However, sanded grout is not water-proof and it must be sealed so that water won't penetrate the porous substance.

Unsanded grout is best used for smaller tiling projects like a shower area or projects with smaller details like mosaics. This type of grout works best with ground joints measuring 1/8" to 1/16" in length. The lack of silica aggregate filler makes this type suitable for projects that use scratchable materials like glass or natural stone.

How Do I Mix Grout?

Proper preparation of the mixture is important above anything else when you are applying grout. You can use just about any tool capable of spreading grout well, but if you fail to follow the correct ratio of grout to water, then the project could easily fail.

By following the instructions correctly as it is said on the package, you can guarantee that the grout mixture will serve its intended purpose well. Below are a few tips you can follow to make a good grout mixture.

  1. Do not blend the grout by hand to avoid a poorly made mixture with lumps and air bubbles.
  2. Use a mixing paddle attached to a reversible drill until it reaches the consistency of toothpaste.
  3. After mixing, let it sit for 5-10 minutes before mixing it again in both directions.
  4. Add the grout gradually into a bucket of water while mixing it so that the grout will not clump up with air bubbles.
  5. To check if the grout is prepared, run a finger over the surface of the mixture. It should be solid enough to create an indentation, and if it returns to its original shape, it's ready.
  6. If your grout can be poured from one bucket to another, it's too thin.

To Warp Up

A man spreads wet cement on a cracked sidewalk

In this article, we learned that there are methods that need to be followed when applying grout. We also discussed a few cement-based grout alternatives you can choose from in order to avoid grout damage in future projects. Make sure that you follow these steps in your next projects so that your next tile work will last longer.

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