What Causes Floor Tiles to Crack?
Unfortunately, floor tile cracks are common in houses. The floor tile crack may actually grow in length or width. When you look around the room, absolutely no other signs of cracks or distress exist. Your house may be less than a year old or 30 plus years old. Immediately, your mind starts to wonder. Do I have a foundation problem? What is causing the crack? Is this serious? What do I do? First, it is important to know that the floor tile is likely installed on a concrete slab or wooden part of a raised foundation, which we call a substrate. In either case, small movements in the foundation may cause the floor tile to crack. Most often, the crack is cosmetic in nature and does not mean you have a structural problem. Second, the floor tile is attached to the substrate with a bonding agent to bond the floor tile to the concrete or wood. By doing so, the floor tile and the substrate essentially become one piece. Let’s take some time to discuss two primary causes of floor tile cracks.
Thermal Expansion and Contraction of the Slab
As with ALL things in a house, thermal expansion and contraction (swelling and shrinking, if you will) of materials occurs. In different parts of the country, expansion and contraction occurs at different rates and magnitudes. So, if we think of a concrete slab with a crack – and let’s face it, all concrete cracks – the concrete crack can expand and contract with the changes in temperature and/or moisture in the soil. When the expansion occurs with a floor tile stuck to the concrete, the expanding concrete may crack the floor tile. This is called reflective cracking. And, the cracked floor tile will then expand and contract with the concrete. Sometimes, the expanding and contracting concrete will loosen the floor tile instead of cracking the tile making the floor tile sound “hollow” when you walk on it.
Caution is urged in calling a contractor to make repairs since diagnosing the causation of these symptoms is more important when these conditions arise. Also, many of these symptoms are similar to conditions that occur with framing problems in a house. Lastly, the conditions discussed are likely to occur in raised foundation houses. That is why, an experienced structural engineer is your best choice to determine the cause of the floor tile crack.
Then, there are other times when a floor tile crack may be a symptom of a much larger, structural related issue. If a floor tile crack is observed with crown molding separations, cabinet separations, and/or wall and ceiling cracks, then the floor tile crack may be associated with differential settlement in your foundation.
Differential settlement happens when areas of the soil supporting your foundation consolidate (squeeze together) or move at different rates than adjacent areas beneath the foundation. This condition creates stress in the foundation, usually in the form of cracks in the slab and uneven floor elevations. If floor tiles are installed on the slab, the tiles will likely crack. Repair methodologies for differential settlement vary from region to region. If you suspect differential settlement has created a floor tile crack in your house, consultation with a structural engineer is highly recommended.
Diagnosing the reason floor tile cracks have occurred in your house takes a seasoned professional who understands the complexities of houses and the physical forces that may be applied to your house. Understanding and diagnosing the reason for a floor tile crack in your house is not typically within the ability of homeowners.