Why Tile Is Cracked and How to Avoid It

Tile can crack for a variety of reasons. Cracked tile is unsightly and can create tripping hazards, so it’s important to understand why tile cracks and how to prevent it. This comprehensive guide will examine the common causes of cracked tile and provide tips on how to avoid tile cracks during installation and thereafter.

What Causes Tile to Crack?

There are several potential causes of cracked tile:

Improper Installation

One of the most common reasons tile cracks is improper installation. Some key mistakes to avoid include:

  • Insufficient Mortar: The mortar layer underneath the tile needs to be thick enough to fully support the tile. Too thin of a mortar layer can lead to cracks.
  • Poor Surface Prep: The surface underneath the tile must be structurally sound, clean, and free of contaminants like oil or dirt. Setting tile on an uneven or dirty surface can prevent proper adhesion and cause cracking.
  • Incorrect Tile Spacing: Tiles need to be spaced apart by a grout joint. Lack of grout joints causes tiles to crack against each other. Conversely, grout joints that are too wide are prone to cracking.
  • Unsuitable Subfloor: Tile should never be placed directly over OSB, particle board, or luan plywood. These materials lack the sturdiness to support tile long-term.
  • Improper Leveling: The tile substrate needs to be precisely leveled to avoid some tiles settling lower than others and cracking.
  • No Movement Joints: Movement joints must be placed throughout the tile field, especially at doorways and transitions between rooms. Movement joints give the tile installation space to expand and contract.

Subfloor Movement

The subfloor provides the foundation for the tile. If the subfloor shifts, flexes, or settles even minimally, it can cause the tile above to crack. Potential subfloor issues include:

  • Wood subfloors that were not properly reinforced to prevent movement.
  • Concrete subfloors that were not given sufficient time to cure before tiling.
  • Deteriorating substrates below the subfloor, such as a cracked slab foundation, shifting the subfloor.
  • Improper fastening of cement board, backerboard, or underlayment to the subfloor causing movement.

Heavy Weight

Some tiles, like natural stone, are quite heavy. Extra heavy tiles require a more substantial mortar bed and subfloor to bear the weight without cracking. High traffic areas also demand sturdier tile assemblies to avoid cracks.

Excess Moisture

Too much moisture under or above the tile surface leads to cracking as moisture causes the substrate to expand and contract. Water damage from sources like leaks or flooding can infiltrate and undermine the tile. In wet areas like showers, proper waterproofing is essential.

Poor Quality Tile

Lower grade tile is more apt to crack, especially with irregularities like uneven thickness. Fractures can form at weak spots in the tile during shaping and firing. Using top grade tile greatly reduces the risk of cracking.

Impact Damage

A significant impact on the tile surface can cause cracks. Dropping a heavy object on tile often results in cracks radiating from the impact site. Use of a cracked or chipped hammer or trowel during installation can fracture tile.

Freeze-Thaw Cycles

In colder climates, freeze-thaw cycles create expansion and contraction that can crack outdoor tiles, stone, and concrete. Sealer and proper installation techniques are crucial for freeze-thaw resistance.

Normal Wear and Tear

Over many years of use, tile can begin to crack from the cumulative effects of regular foot traffic and cleaning. Glossy tiles tend to crack more readily than textured tiles under long-term use.

Tips to Prevent Cracked Tiles

Cracking can be minimized or avoided by following best practices during installation and properly maintaining the tile thereafter:

Select High Quality Tile

Carefully inspect tiles prior to purchase for any cracks or defects. Check for an ANSI quality grading certification and buy the highest grade tile within your budget. Avoid thin or irregular tiles prone to cracks.

Choose a Durable Tile Material

Porcelain, ceramic, and natural stone tiles are very durable options, while glass and metal tiles are more prone to cracking. Mosaics are beautiful but require flawless substrates and expert installation to avoid cracks.

Allow Proper Tile Spacing

Leave a minimum 1/8” grout joint between tiles, more for larger format tiles, to allow room for movement and prevent cracking. Use tile spacers to maintain even grout line widths.

Prepare the Subfloor Properly

For wood subfloors, ensure adequate thickness, reinforce with backerboard, and fasten correctly. Concrete must be cured at least 28 days before tiling, smoothed to a “1/4 in 10 feet” maximum tolerance, and free of contaminants.

Use a Suitable Mortar

A polymer-modified thinset offers flexibility and bonds well for stable installation. Using premixed mastic or the wrong type of mortar jeopardizes adhesion. Mix to proper consistency and regularly replace mortar while tiling to prevent premature hardening.

Apply Mortar and Tile Correctly

Fully embed each tile in a thick, even layer of mortar applied with the proper trowel notch size. Beat or back-butter tiles to maximize mortar contact and work neatly to avoid cracked edges.

Install Movement Joints

Place expansion joints around perimeters, at transitions between rooms, and about every 20 feet in larger tile fields to allow shifting without cracking tile. Use an open or soft joint filler, not grout.

Cure Grout Thoroughly

Allow grout to cure fully (typically 28 days) before exposing tile to heavy use or moisture. Insufficient curing causes grout to crack, which transfers stress to the tile edges.

Seal Grout and Tile

Sealing the grout and some natural stone or porous tile prevents moisture intrusion that can undermine the tile and cause cracks. Reapply sealer periodically.

Limit Moisture Exposure

Protect tile from water damage by sealing grout and addressing any leaks promptly. In showers and steam rooms, install an effective vapor barrier and slope floors to drains.

Handle and Clean Tile with Care

Heavy objects hitting or scraping the tile surface can cause chips and cracks. Use only non-abrasive cleaners and soft scrubbing pads when cleaning.

Check for Loose or Cracked Tiles

Inspect tile installations periodically for any loose, cracked, or damaged tiles and re-adhere, replace, or repair them immediately to prevent further cracking.

With proper installation techniques and care, tile floors and walls can remain beautifully crack-free for decades. Paying close attention to subfloor preparation, mortar application, grout curing, and preventing damage allows tile to live up to its durable, low-maintenance reputation. Carefully following tile best practices well rewards homeowners with a lasting, high-quality installation.

FAQs About Cracked Tile

What causes cracks in floor tiles?

Some top reasons floor tiles crack are weak subsurface or substrate shifting, improper installation, lack of movement joints in large tile fields, uneven tile surfaces causing stress points, excess moisture exposure, and normal long-term wear.

Can cracked tiles be repaired or do they need replacement?

It depends on the extent, location, and cause of the cracking. Light cracks in grout lines can often be patched with fresh grout. Cracked tiles on floors usually require full replacement to avoid safety hazards. Wall tiles with minor cracks not near edges may be reparable with crack fillers.

How long after installation can tile cracks appear?

Cracks immediately after installation typically stem from improper mortar curing or installation errors. Cracks weeks or months later point to subfloor movement. Years later, cracks develop from wear, improper maintenance, accidents, and subfloor deterioration over time.

Should tiles be replaced all the way to the wall if there are a few cracked ones?

Replacing only the cracked tiles often results in poor matches with the old tiles and noticeable transitions. It is better to replace the full row of tiles from the wall to a grout line past the damage for a seamless appearance.

Can cracked shower tiles allow water damage behind walls?

Definitely – cracked shower tiles provide an entry point for water to infiltrate and cause unseen rot, mold, and mildew in walls or subsurfaces. Damaged shower tiles should be promptly repaired or replaced to prevent larger water damage issues.

What flooring material is least likely to crack?

Sheet vinyl, luxury vinyl plank, and linoleum are all quite flexible and unlikely to crack under normal conditions. They can conform to minor subfloor imperfections. Ceramic and porcelain tile resist cracks well but require flat, stable substrates.

Causes of Cracked Tile by Location

Cracked tiles can occur anywhere in the home but certain tile locations come with unique risk factors.

Kitchen Tile Cracks

Heavy foot traffic, shifting foundations, subfloor moisture, and accidents during remodeling or drops by cooks make kitchen tile susceptible. The best defense is proper prep, installation, grout curing, joint placement, and sealants.

Bathroom Tile Cracks

Bathroom tile endures near-constant moisture. Grout and tile must be sealed thoroughly. Insufficient waterproofing under bath and shower tile often contributes to cracks when water infiltrates the subfloor.

Outdoor Tile Cracking

Freeze-thaw cycles, outdoor furniture scraping across its surface, ground movement due to roots or poor drainage, and harsh weather exposure can harm outdoor tile. Using frost-resistant materials and proper joint installation helps prevent cracked patio or walkway tiles.

Fireplace Tile Cracks

Fireplace tile must withstand substantial temperature fluctuations. Use special high-heat mortar and grout for fireplace tile installations. Leave ample movement joints around the entire fireplace.

Cracked Subway Tile

Long, thin subway tiles are prone to cracking unless the substrate and tiles themselves are completely flat and stable. Minor wall shifts can crack rigid subway tile. Use premium tiles and proper spacing to minimize subway tile cracks.

Floor Tile Crack Repair

Some methods to repair cracked floor tile include:

  • Fill thin cracks with epoxy filler products.
  • Carefully lift and re-adhere cracked tiles fixed in place with new thinset.
  • Remove and completely replace cracked tiles and surrounding grout lines.
  • Apply mesh tape and epoxy filler beneath cracked sections before replacing tiles.
  • Consult professionals for extensive cracking – a new tile floor may be required.


Tile cracks most often stem from installation errors, substrate movement, excess moisture, freeze-thaw cycles, dropped objects, and simple long-term wear. Careful prep, high-quality mortar and tile, proper grout curing, movement joints, sealants, and gentle cleaning reduce the risk of cracked tile floors and walls. Minor cracks can often be repaired by reheating, filling, or replacing individual tiles. Extensive cracking may necessitate professional help or re-tiling the entire surface. With care and diligence during installation, tile can deliver decades of beauty in any home without the eyesore of damaging cracks.

So in summary, the main ways to prevent tile from cracking are:

  • Allow proper tile spacing with grout joints
  • Prepare subfloors correctly
  • Use suitable mortar and apply properly
  • Install movement joints
  • Limit moisture exposure with vapor barriers and sealants
  • Handle, clean, and maintain tiles gently
  • Inspect for loose or cracked tiles frequently

Taking the right installation and care steps allows tile to live up to its reputation as a durable flooring, wall, countertop, shower, and backsplash material. With attention to tile best practices, you can confidently install tile that will remain resiliently crack-free for many years of beauty and enjoyment.