Key Takeaways:

• Learn to distinguish between installation flaws and structural movement.
• Use the “coin tap” test to diagnose tile cracks.
• Understand when it’s a cosmetic fix vs. a foundation repair.
• Discover why kitchens and bathrooms are most affected.
• Know when to call a foundation expert.

How to Tell If Your Cracked Tile Is from Bad Instal or Foundation Issues

Kitchen and bathroom tiles form cracks for various reasons, but what may start as a cosmetic imperfection can lead to more serious damage if the underlying issue isn’t addressed. Learn the science behind these cracks, what they mean for the rest of your home, and how you can resolve the issue before it gets worse.

Why Tile Cracks Happen

Cracks in floor tile usually fall into one of two categories: installation issues or foundation issues.

Common Installation Errors

Improper insulation can cause the tiles to crack under pressure as they expand or contract with temperature changes. It’s important to apply enough thinset mortar to ensure the tiles bond properly to the underlying surface. Gaps in the mortar make it more likely for the tiles to shift out of place. 

The tiles should also be installed on a concrete backer board rather than bonding directly to the plywood. This insulates the tiles from the plywood, which will contract and expand naturally as temperatures change. 

Drastic temperature changes can also cause some tiles to expand, putting stress on the installation. Embedding expansion joints in the tiles gives them room to breathe. It allows the building’s materials to move naturally, preventing cracks from forming.

Foundation Movement and Soil Shifts

Cracking and tile movement may also be a sign of foundational issues, mainly due to soil compaction and expansion. As the foundation settles or becomes uneven, it puts stress on the rest of the home. The tiles may be the first items to slide noticeably out of place, especially if they weren’t installed correctly. 

Relaying or patching the tiles may only temporarily solve the issue. They will likely crack again if the foundation continues to shift.

The Risks of Cracked Tiles and Why They Need to Be Fixed

Cracks in tiles may seem like a minor inconvenience, but they can be a danger to your guests and loved ones the longer they go unaddressed. Air and moisture can accumulate in cracks, especially in highly moist environments like the kitchen or bathroom, leading to mold growth and further movement or separation. They can also become tripping hazards if they slide out of place or come up off the floor.

The “Coin Tap” Test: Your First Clue

The coin tap test can help you determine the extent of the damage to your kitchen or bathroom tiles, including whether they are properly bonded to the subfloor. It’s a simple assessment that can easily be performed at home without professional assistance.

How To Perform It and Interpret Sounds

You’ll need a coin, usually a quarter, or a metal tool, such as a screwdriver, wrench, or small hammer, to tap the tiles. Gently tap the center and the corners of the tile with the metal, and listen for the sound. 

A sharp, ringing sound means the tile is intact and securely bonded to the subfloor or concrete backer. A thud or hollow, drum-like sound means the tile has come loose and is no longer attached. You can follow up by pushing against the tile to see if it moves. Tap a secure, solid tile to develop a baseline before testing tiles that may have come dislodged.

Reading the Crack Shape

Once you perform the coin tap test, assess cracks in the floor tile to investigate the underlying cause. Each type and style of crack can tell you how it was formed.

Jagged Vs. Hairline Cracks Explained

Hairline cracks are generally less than a millimeter wide. They appear straight or in web-like formations and usually indicate installation issues, such as improper bonding or insufficient expansion joints that allow for natural, subtle movements. These types of cracks are easy to fix and don’t usually indicate larger foundational issues.

Jagged cracks are typically wider, often thicker than a quarter of an inch, rippling across tiles in jagged streaks like lightning bolts. They are caused by foundation settling as the soil compacts and expands with the freeze-thaw cycle. Excess moisture can also cause the underly soil to erode and may indicate a kitchen or bathroom slab leak caused by water or sewer pipe failure. Jagged cracks are a high priority and may represent severe structural issues.

What Long Cracks Across Multiple Tiles Mean

Long cracks across multiple tiles indicate extreme foundation problems. They are often caused by cracks in the concrete slab beneath the house that extend through the tiles. There may be excess moisture under the foundation due to a burst pipe, poor drainage, or excess runoff.

Why Wet Areas Crack First

Kitchens and Bathrooms as Soil Stress Zones

When kitchen and bathroom tiles crack, moisture is usually to blame. The pipes bringing water to and from these rooms can leak, allowing water to seep under the home’s foundation. This causes the soil around it to settle and erode, leading to extensive damage as the concrete breaks or slopes downward.  

You may experience a higher-than-usual water bill, low water pressure, or notice warm spots on the floor where the hot water is leaking. Kitchen and bathroom slab leaks can lead to mold, damp carpets, and warped floors.

When to Call a Foundation Professional

If the cracks indicate a problem with your home’s foundation, call a kitchen foundation repair professional to have them assess the slab’s structural integrity. Foundation issues often lead to uneven floors, bowed walls, and gaps around doors and windows.

What a Slab Evaluation Involves

The professionals will use various methods to determine what’s happening beneath your kitchen or bathroom floors. They will examine the floor’s flatness, surrounding moisture levels, the position and extent of the cracks, and the floor’s overall structural integrity. They may also use a ground-penetrating radar system to detect subsurface features beneath the foundation and/or a slab impact response system to detect cracks and hollow spots in the concrete slab. 

Repairing the foundation will prevent future cracks and improve your home’s structural integrity.  The slab will continue to settle and shift the structure without professional assistance. Contact the pros at Perma Pier to schedule a free kitchen foundation repair inspection today!

FAQs:

1: How can I tell if a cracked tile is due to foundation problems?

The size and shape of the crack can help you determine if it is a symptom of foundational issues. Thin, hairline cracks generally result from installation problems, while larger jagged cracks and long cracks across multiple tiles indicate foundation issues. 

2: What’s the “coin tap” test, and how do I do it?

The coin tap test is a simple test used to determine if tiles are firmly attached to the subfloor. Tap a coin or metal tool around the edges of the tile. A sharp, tinging sound means the tile is secure, while a dull, drumming sound means it has been dislodged. 

3: Do cracked tiles always mean structural damage?

No, some cracks form as a result of poor installation, including improper binding, gaps in the thinset mortar, binding tiles directly to the plywood instead of a concrete backboard, and not using expansion joints that allow for movement. 

4: Can foundation repair fix floor cracks?

Foundation repair helps treat the underly cause of the cracks and prevents them from cracking further, but the tiles will still need to be replaced or patched. 

5: Should I replace tiles before or after foundation repair?

You should only replace broken tiles after the foundation has been repaired. If you replace the tiles first, an uneven or shifting foundation may cause them to crack again.