Slow Draining Sink

Causes of a Slow Draining Sink

Whether you own or rent your home, you will eventually have to deal with a slow draining sink. A slow draining sink is caused by a partial clog, which is a clog that doesn’t completely stop the entire flow of water down the drain, but instead slows it down significantly. Partial clogs almost always build up over time. You may notice that the drainage slows slightly at first, but becomes slower and slower over time.

So what is actually causing the blockage? Well, it’s usually a slimy, disgusting mix of personal care products, soap scum, mildew, and maybe even solid debris.


If you have hair of any length, you’ve likely noticed that you can find it all over your bathroom. You shed more hair in the bathroom than anywhere else in your home because the bathroom is typically where people brush their hair. Some of those hairs flying all over your bathroom make their way down the sink drain. If you commonly rinse hairs down the sink, you’re making the problem worse. Once in the sink drain, hairs stick to the sides of the pipes or get caught up in the screen or trap.

Personal care products

Hair products like gels, pomades, and sprays also end up in your drain, adding to the stickiness of the pipes and making hair more likely to stick.

Toothpaste is another common culprit of partial drain clogs. We all spit our toothpaste back into the sink, but when there’s already hair and other sticky substances starting to build up in the pipes, toothpaste can actually contribute to the problem.

Shaving creams, foams, and gels are just like hair products in your drain. They form a sticky, gooey mass that catches everything that comes near it. While you may be tempted to rinse those beard hairs and shaving cream down the sink drain, it’s better to put it in the trash.

Soap scum and mildew

If you don’t clean your bathroom or kitchen fixtures for a couple of weeks, you’ll undoubtedly notice a gross, slimy film covering all the surfaces. That’s a nasty combo of soap scum, mildew, and sometimes even mold, that accumulates on any surface where you frequently wash things, like your kitchen and bathroom sinks. Given enough time, soap scum and mildew will build up on the sides of pipes until they actually shrink the opening, which causes water to drain slower and makes it easier for debris to become trapped.


Most sink drains come with a top that stops large items from making their way into your pipes. Sometimes, that top is missing, or a piece of debris is just small enough to make its way around it. This is especially common with food debris in kitchen sink drains, but anything can be shoved in a drain. Just think of all the things a toddler would love to drop into a sink drain and watch disappear! The trap under the sink usually catches these larger items, which is why you should regularly check the traps under all of your sinks (it’s the U-shaped pipe). However, if your pipes already have a partial clog forming, large debris may never even make it to the trap. When this happens, you’ll notice a sudden, sharp decrease in water drainage.

You may be tempted to run out and grab a bottle of commercial drain cleaner to fix a slow draining sink, but that can actually be more harmful than beneficial, especially if you have older pipes. Instead, trust the ace team at Friend’s Plumbing to discover the exact cause of your slow draining sink and remedy it without any damage to your plumbing. We’ve been helping Tampa Bay residents with all their plumbing needs since 1979, and we have the tools and experience to fix anything from a slow drain to complete plumbing replacement. Call us at (727) 934-0323 or click here to contact us for an estimate on your plumbing repair. We also offer 24/7 emergency services, so you’ll never have to spend the weekend without hot water or a functioning toilet.