Cracks in a sink are quite common, and they typically start out as small hairline fractures that develop around the drain. In most cases, the cracks aren’t all that big of an issue despite being unsightly. However, there are times when they can grow large enough that water may start leaking out around the drain. The good news is that cracks in a sink are usually quite easy to avoid, and this article will show you what issues typically lead to a sink cracking so that you can do just that.

Thermal Stress Due to Rapid Temperature Fluctuations

Metal sinks like those used in most kitchens may rust, but they typically won’t ever crack. Porcelain and stone bathroom sinks, on the other hand, can be prone to cracking. One of the most common reasons that these types of sinks develop cracks is due to thermal stress. Thermal stress occurs when there is a rapid fluctuation between hot and cold temperatures. Porcelain is especially prone to fluctuations in temperature, which is why you should never pour boiling water into your bathroom sink.

Most materials tend to expand and contract as the temperature fluctuates. This expansion and contraction are usually minor and won’t put undue stress on the material, but it can lead to cracking when there is an extreme, rapid fluctuation between hot and cold or cold and hot. For instance, if you plug up your bathroom sink and fill it with hot water, porcelain or stone will absorb lots of heat from the water. This will lead to the sink quickly becoming quite hot and the material expanding slightly. If you drain the sink and immediately fill it with cold water, the porcelain or stone will then contract. This rapid contraction puts extra stress on the sink and can cause a hairline crack to immediately form around the drain. Even if the sink doesn’t immediately crack, the rapid expansion and contraction can still weaken it so that small cracks eventually develop over time.

Porcelain and stone sinks can also get quite cold in the winter, especially if you turn your heat down overnight. If you ran extremely hot water in the sink when it was cold, the material could also expand rapidly enough that it starts to crack. One way you can help to avoid this issue is to never set the temperature on your water heater higher than 130 degrees.

It’s also a good idea to never immediately turn the water on as hot as it will go when your sink is quite cold. Instead, you should first turn the water on so that it is warm or only slightly hot and then let it run for 15 seconds or so before you start running fully hot water. This will enable the sink to heat up and expand at a slower rate, which puts less stress on the material, so it is less likely to crack.

In most cases, the cracks will only develop in the enamel coating on the porcelain. This means they typically won’t cause the sink itself to crack and start leaking. However, the cracks can continue to grow over time to where the sink does start to leak, which is why it’s a good idea to get the cracks repaired as soon as you notice them.

If you have a stone sink, you should be especially careful about not subjecting it to rapid temperature fluctuations. Natural stone is beautiful, but the issue is that stone often has weak spots that can lead to the whole sink cracking and leaking. Should this happen, your only option will typically be to replace the sink. These weak spots can also lead to stone sinks naturally cracking over time even without temperature fluctuations. If you spot the issue early enough, you may be able to repair the cracks before they grow bigger and force you to replace the sink.

Acid and Harsh Chemicals

You should also make sure that you never pour any type of acid or harsh chemicals into your sink. Toilet cleaners and other cleaning agents that contain harsh acids can easily damage a sink. Those chemicals weaken the sink, allowing cracks to form over time.

Chemical drain cleaners are even worse and should never be used in any sink, drain or toilet except as a very last resort. The chemicals in any type of drain cleaner are extremely harsh and can lead to major damage to your pipes and plumbing. Any time you use drain cleaner, the chemicals can start to eat away at the pipe and severely weaken it or cause it to leak.

Not only can drain cleaner damage your pipes, but it can also easily cause porcelain sinks to crack. Many drain cleaning products contain sodium hydroxide, which produces an exothermic chemical reaction when it comes into contact with water. This reaction releases a huge amount of heat almost instantly, and this heat can again cause the sink to rapidly expand and potentially crack. The same thing can happen any time you put drain cleaner in your toilet. All the heat from the chemical reaction is another reason to avoid using drain cleaner as the heat can easily cause PVC pipes to warp and start leaking.

Overtightening the Drain

Porcelain is quite fragile and can easily crack simply by dropping something heavy on it. It can also easily crack if you were to overtighten any fittings or connections, such as the drain piece. Similarly, many people end up causing their toilet to crack by overtightening the nuts and bolts that secure it to the floor.

The metal drain on a bathroom sink will often start to rust over time and make the sink look unsightly. The drain can almost always be replaced without having to install a new sink. However, we would always recommend having a plumber replace the drain for you to ensure that you don’t crack the sink when installing the new drain piece. If you were to install it yourself and overtighten the fitting, there is a high chance the sink will crack. If this happens, you’ll then need to hire a plumber to replace the entire sink, which will obviously cost you a lot more than if you’d just hired a plumber to replace the drain in the first place.

If you need any plumbing services in the Denver area, High 5 Plumbing, Heating & Cooling is always here to help. Our team of licensed plumbers specializes in all residential plumbing services, and we can help if you need to replace your sink or install any other plumbing fixture. We also offer professional drain cleaning and sewer services and can take care of your plumbing repair and maintenance needs as well. No matter what type of plumbing service you need, give us a call today to get the professional, prompt service your home deserves.

High 5 Plumbing

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