toilet clog causes, common toilet clogging causes

Toilet Clog Causes

6 Common Toilet-Clogging Culprits

The toilet is one among the most commonly used fixtures in anybody’s home which implies that if it’s clogged, it can be the end of the world—with a terribly unpleasant cleanup.  

Getting a hold of why the toilet acts up can assist in the prevention of future blockage and keeps the plunger wherever it belongs: far from the toilet.  Watch out for these 6 toilet clog causes!

1. Semi and Non-Flushable Items

The primary reason for a toilet clog is toilet paper.  When using massive quantities of toilet paper, it's best to first flush the waste then follow with a flush to get rid of the toilet paper. 

Also, fold the paper to produce the specified thickness, instead of making a ball.  The tightly bound balls of toilet paper usually are too large to fit through the narrow diameter trap. Minimizing any toilet paper used will just about eliminate toilet paper clogs.  

Ended up with a clog anyway?  Begin by giving it a decent plunge with a toilet plunger.   Particularly stubborn clogs might need bringing in professionals (like us) to snake the drain. 

Tampons and sanitary napkins or pads are also typical reasons behind a toilet clog. 

Tampons are designed to absorb wetness and expand.  It can do exactly that in the toilet trap. 

Take note that most sanitary pads have plastic fibers. These cannot dissolve easily and the sheer size of most napkins forestall passage through the narrow diameter trap. 

Call us immediately should the toilet become clogged by these items as the only certain fix is to snake the drain to get rid of the culprit.


Another cause of a clogged toilet is a large clod of human hair or pet fur.  Have a habit of flushing hair from the brush down the toilet? Break it now!  Has continual flushing of clumps of hair clogged the toilet? Snaking will fix it.

toiet clog causes toilet overflow

2.  Jammed Trap

All drain pipes have what is known as a trap.  The trap is an S-shaped tube that separates your toilet from the drain line—a bend in the piping that remains filled with water.  This water acts as a disinfectant against bad odors that might otherwise drift into the house from the sewer lines. 

The trap also keeps nasty sewer gases from getting into the house.  Toilet traps are effective at doing this task, but unfortunately, the bend in the pipes is also a prime target for clogs to occur. 

Using too much toilet paper can result in a clog developing in the trap no matter how carefully toilet paper is flushed down the toilet. 

As an example, imagine a toothbrush was flushed down the toilet, it could be stuck in this trap.  Then, each time it’s being flushed, more debris gets wrapped around this object, eventually leading to a clog.  A plunger may be able to solve the issue by sending all the debris down the sewer drain, but the toothbrush stays in the trap because its shape makes it difficult to get through the S-curve. So, this could be a recurring problem.

3. Flapper Trouble

toilet clog causes flushing mechanism

The flapper is a round rubber gasket that sits at the bottom of the toilet tank and controls the flush of the toilet.  This opens during a flush, which allows the water to run into the bowl.  

It is the part of the toilet that lets water flow from the tank on the back down into the toilet bowl, creating the flush. 

If the flapper in the toilet is out of whack, it may be defective by closing too soon and reducing the power of the flush.  If the flapper doesn’t open all the way it cannot discharge enough water, which means it will provide a weak flush.  

Clogs are common in toilets with a weak flush by failing to thrust the contents of the bowl far enough down the drain pipe. 

The flapper is usually attached to the flush handle with an adjustable chain.  An easy fix is to move the chain a few links to shorten it and try a test flush.  Lift up the cover of the tank, flush the toilet and keep tabs on the movement of the device inside the tank.  

Observe to see three fourths (3/4) of the tank’s water drain before it closes.  The flapper will need replacing if it’s closing too early.

4. Low Flow Toilets

For many years now, homeowners who have wanted to conserve water have installed low flow toilets in their homes.  Sadly, the early models were not as efficient as the ones that are available today.  

Similar to the flapper’s troubles above (Common Toilet-Clogging Culprit #3), low flow toilets may not flush strongly enough to push the contents fully down the drain.  Most of these old generation low flow toilets lack the needed force to clear the trap and drain, resulting in usual clogs. 

Low flow toilets only use about half of the quantity of water compared to full flush ones.  It may be that the toilet cannot take the load it’s being given like human waste or Semi and Non-Flushable Items (Common Toilet-Clogging Culprit #1).  

In the case of clogs, the flush is likely too wishy-washy to handle what’s being doled out to it.

A dual flush toilet enables the toilet to flush with more water, normally by holding the handle down longer than usual.

To check for an efficient low flow toilet, and the age of your toilet, look at the back of the toilet for a stamped date.  If the toilet was made in the mid-90s, it could be a first-generation low flow toilet. If this is the case, don’t feel the need to rush into a replacement.  

Two possible ways to reduce clogs in low flow toilets are by reducing the amount of toilet paper used per flush and avoiding clog-prone items.

toilet clog causes toilet repair

5.  Obstructed Plumbing Vent

All toilet drains vent out to the roof.  Contemporary toilets use roof vents to displace fresh air into your plumbing system and boost flushing pressure.  This helps the toilet get a satisfactory flush. 

Over time, these vents can become clogged with several objects like leaves, sticks and even animal nests.  If the vent becomes clogged or blocked, there’s less pressure thus making the toilet flush slowly.  

A blocked toilet vent will reduce flushing pressure and cause regular clogs.  And that weakened velocity means larger “gobs” don’t quite get flushed entirely, setting to a continual clog problem. 

It’s best to hire a pro like So Cal Services to clear those plumbing vents.  Blockage can be hard to identify and may need special tools to get rid of.

6.  Issues with the Sewer Line

Regular clogs in several toilets and drains are typically the sign that there’s a sewer line problem.  Clogs are usually caused by a buildup of waste matter, toilet paper, and non-flushable items (Common Toilet-Clogging Culprit #1).  

However, tree roots can grow into the sewer line and create a backup.  These roots can also pierce the sewer line, letting in sediment and many more obstruction-causing junks. 

There can also be a partial clog in a sewer line that is never quite removed when plunging. Sewer line problems can cause a great deal of issues inside and outside of the house.  

A sewer line clog can even threaten the health of any family under the roof.  It’s best to hire a professional to fix any sewer-related issues. ​

Though toilet clogs can be unpleasant and messy to clean up, it’s not the end of the world!  

For more plumbing help tips, read How To Avoid Costly Plumbing Repair

Need help with a clogged toilet or experiencing an excessive number of clogs?  Contact the friendliest plumbing professionals at So Cal Services today at 915-926-1978 (24/7 Emergency Service) or reach out to us via email

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