What to Do When Bathroom Tiles Start Cracking from Humidity

If you live in a rainy zone, you may be surprised to enter your bathroom and discover something unexpected—a couple of cracked tiles, some of which may be warping or tenting. The culprit is humidity, which can seep through grout lines and gaps between your tiles and the wall, causing breakage. The reason this issue may not show up for years is that it takes repeated cycles of expansion (in hot weather) and contraction (in cold weather) to weaken the grout and tile bonds. And the reason why cracks may appear suddenly is that very often, once tiles are separated from the wall, it can take very little for them to start falling. Moreover, cracking may also result from other causes, including poor installation and structural movement.

Signs of Humidity Problems in Your Bathroom

In addition to cracking, humidity issues typically include other signs, such as discoloration, wobbly tiles, and a persistent damp smell in your bathroom. If mold grows on the ceilings or tiles, it is a good sign that your bathroom lacks adequate ventilation. Grout lines themselves may develop cracks, and you may notice pain or damage to the plaster near your tiles. If only the grout is affected, it is easy to remove it, clean the area, and regrout with waterproof grout. However, if tiles are cracked and falling, or there is a significant empty space between the tiles and the wall, the only long-term solution is to renovate your bathroom and retile it. 

Identifying the Cause of Humidity

Before engaging in renovation work, it is vital to discover the exact cause of the humidity. For instance, your bathroom may lack ventilation if the window is too small. In this case, it pays to ask your renovators to include a powerful exhaust fan and, in some cases, to consider replacing your window with a larger one that will allow vapor to escape. In some cases, faulty plumbing is to blame. Pipes, joints, or valves can allow small amounts of water to seep into the tile backing material, causing it to swell. As pressure builds up, tiles begin to crack, loosen, or lift. In this case, a plumber should address leaks and other potential issues before aesthetics come into play. It may also be helpful to check sludge and rust buildup in your central heating system, as these issues can indirectly contribute to pipe leaks by creating pressure and circulation problems that can stress the system.

Choosing Your New Tiles

When selecting your new tiles, consider those made of a material that resists moisture and humidity well, such as porcelain or ceramic. For flooring, textured or matte tiles will help you keep your footing, especially in showers and around your bathtub. To ensure your choice will last for many years to come, check the durability ratings of different tiles and select those specifically made for high-moisture zones.

The Need for Preparation

If your plumbing is in order, you can get ready to work on retiling your bathroom. Proper preparation is key, as the substrate (the part of the wall that tiles are affixed to) must be stable and flat. Your bathroom specialists may suggest using cement backer board or specialized waterproof boards, as they resist moisture better than standard drywall, and they provide tiles with a strong bonding surface. Prior to installation, it is important to clean the surface and secure it to a completely level, smooth substrate. Next, it’s time to seal the joints between backer boards, apply waterproof membranes around showers and tubs, and protect corners and seams with waterproof tape.

Applying the Tiles

Once your tiles have a flat substrate to adhere to, it’s time to apply adhesive and press the tiles into place. Next, grout is used to seal the gaps between tiles. The bonus is that it also boosts water resistance and lends structural stability to the tiles. Next, the grout must be sealed with a protective sealer to keep moisture, stains, and mold at bay.

If the tiles in your bathroom are cracking or bending toward you, chances are, humidity is to blame. It is vital to inspect your bathroom to determine the cause of this issue; sometimes, plumbing issues, rather than general humidity, are to blame. If retiling is necessary, make sure to invest in a solid, flat, waterproof base and choose tiles that are durable and moisture-resistant.