10 Reasons Why Your Floor Tile Grout Is Cracking

Giovanni Valle is a licensed architect and LEED-accredited professional and is certified by the National Council of Architectural Registration Boards (NCARB). He is the author and managing editor of various digital publications, including BuilderSpace, Your Own Architect, and Interiors Place.

Grouting doesn’t only help tiles stay in place, it also makes tiling more beautiful. Generally, a good quality grout passes the test of time and serves for an extended period if installed correctly. However, it can break or crack over time due to various reasons.

Here are 10 reasons why your floor tile grout is cracking:

Grout has stood the test of time.
Water has taken a toll on it.
Faulty installation.
Bad quality of grout.
Damage by acid cleaners.
Improper underlayment.
Seismic disturbances.
Nearby construction activities.
Post-installation mistakes.
Insufficient thinset.

Let’s look deeper at the reasons and find out why your floor tile grout is cracking. As you get to know the exact cause, it’ll be easier to find the solution.

1. Grout Has Stood the Test of Time

Grout is solid and durable. It keeps the flooring together for extended periods. However, after serving its time, it can start cracking. In that case, grout needs to be replaced, and regrouting will be the only solution.

It may take more than 15-20 years before you could notice any cracks on the floor, even if it has been taken care of properly. If you don’t take care of it properly, grout will have a shorter life span.

High-traffic areas such as galleries, entries, hallways, etc., tend to break more easily than low-traffic areas.

2. Water Has Taken a Toll on It

Water is one of the enemies of grout. Small water molecules and other minerals present in it slowly make their way into the molecular space of grout and break the bonds. Over time, this process results in the floor crumbling.

When water, oxygen, and sunlight combine, they can accelerate the deterioration of grout. Most vulnerable places of this type of deterioration occur in washrooms, near swimming pools, the kitchen sink, or anywhere the water retains or flows constantly.

Keeping the grout dry as much as possible can save it from cracking earlier. The good news is that a relayering of grout can solve this issue without much hassle. However, it’s advised to call a professional to regrout the floor.

3. Faulty Installation

Sometimes, it can be a mistake on the expert’s side. If the installation hasn’t been done correctly, grout tends to break in a few weeks or months.

Faulty installation can include the imbalanced grout mixture, too much water in the grout (or on the floor while laying grout down on the floor and jointing tiles), wrong timings of water exposure, and seasonal activities.

There are so many factors in faulty installation, and it might be challenging to figure out the exact cause of grout breaking. Asking a professional or the one who installed the flooring in the first place can pinpoint the issue and help find the solution.

4. Bad Quality of Grout

This reason is the most annoying one. You took care of everything. The installation was perfect. You took care of the floor after installation. However, there’s an issue with the quality of the grout.

Poor quality grout won’t stand for long, and the tiles may begin to warp over time. If you know that bad quality is the only culprit, please remove the previous grout before regrouting. Otherwise, good-quality grout wouldn’t be able to make its grip correctly.

It’s best to take advice from the retailers or manufacturers before choosing the grout. They can help you choose the perfect grout as per your needs.

5. Damage by Acid Cleaners

Like water, oxygen, and sunlight, acid is another rival of the grout. If you’re a clean freak and regularly clean the floor with harsh acid cleaners, I have bad news for you. The reason for grout floor cracking might be a result of excessive cleaning.

Muriatic acid or hydrochloric acid is a very harsh and corrosive solution. Some DIY videos suggest using it to clean the grout floor quickly. However, muriatic acid can damage the grout beyond repair and the only solution left is to regrout the whole floor.

Moreover, acid cleaners can fade away the natural shine of the porcelain or natural stone tile. It is always best in this situation to use gentle cleaners to clean the tiling.

6. Improper Underlayment

When tiles are placed on the layer of grout or mortar, the backside of the tile sometimes remains hollow, and the strong bond between the subfloor and tile isn’t achieved.

Improper underlayment can result in weak bonds, grout can break off on the sides, or the tile may get loose over time.

To avoid this situation, the back buttering of the tiles is crucial. Back parging gives extra strength and grip to the tile and keeps grout away from cracking.

7. Seismic Disturbances

Seismic disturbances such as earthquakes can create cracks in the floor grout. When the earth’s crust vibrates due to any seismic activities, it could loosen up the bonds of tile and grout. Hence cracks and seams start appearing.

If seismic disturbances are the reason for your grout cracking, you might know it through news or self-experience. Even if the quake’s intensity was not high, it could result in the chipping of the floors.

8. Nearby Construction Activities

Just like the seismic disturbance, the use of heavy machinery for digging or demolishing a building nearby your house can create the same effect of crust vibrations as in earthquakes and other natural disturbances.

If the nearby construction or demolition activities harm your private property, you can contact the relevant authorities and stop the destructing activities as soon as possible to avoid further disaster.

You can ask the neighbor concerned to regrout your floor for the destruction that has already occurred. Alternatively, check your insurance policy for compensation details.

9. Post-Installation Mistakes

Post-installation mistakes include the exposure of grout to water, sunlight, or other seasonal activities without having the grout set properly.

However, there can be some other later installation mistakes, such as keeping the area wet for extended periods, using harsh chemicals, exposing the site to UV lights, or accelerating grout deterioration by any means.

10. Insufficient Thinset

Thinset is an adhesive substance that bonds tile, subfloor, and grout. It’s mixed with grout at the time of flooring.

If thinset was insufficient in the grout mix, it might result in the grout chipping within a short space of time. There might be seams between the tile and the grout.

If you’re determined to avoid all mistakes to make your tile grout flooring long-lasting, you may want to remind the installation technician before mixing the grout.

However, if your grout has already been cracked and you are finding the cause, insufficient thinset may be the reason.