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Caulk Around Toilet Turning Brown! Why And How To Fix It

Caulk around the toilet turning brown is never a good sign. It can mean that you need to remove the toilet and check for leaks.

Let’s take a look at why the caulk is brown and what you can do about it.

Caulk Around Toilet Turning Brown

The main reason for caulk around the toilet turning brown is because the toilet has been leaking for a while. This means that waste has started to discolor the caulk around the base of the toilet.

Why Is The Caulk Around The Toilet Turning Brown?

When we first saw that the caulk around our toilet was going brown, we wanted to gag.

We had just moved in, so the discoloration had been from the previous owners. Unsurprisingly, we wanted to get rid of this issue as soon as possible. 

If you see that the caulk around the base of your toilet is brown you may be concerned. It usually means that the wax ring around the toilet has failed, and the toilet is leaking. 

The resulting brown staining is coming from the human waste going into the toilet. This is both unpleasant and unsanitary, so it’s necessary to rectify the problem very quickly. 

Causes Of Caulk Turning Brown

The wax ring is the seal that sits between the opening of the toilet and the toilet flange. This is sometimes called the closet flange. A wax ring is used because it better resists bacteria and mold. 

If the wax ring does fail then water will leak out around the toilet flange and discolor the caulk around the toilet. 

Can You Whiten Caulk Around Toilets?

It is possible to whiten the caulk around the toilet if you have just noticed it. There may be some slight yellowing of the caulk bordering on brown. 

However if it goes unnoticed for some time the discoloration may get to a point where it isn’t possible to whiten the caulk again.

But if you catch it early you should be able to get the caulk back to its original color.

How To Whiten Caulk

As soon as you notice any staining of your caulk grab a bucket and fill it with a gallon of hot water. Add a quarter cup of bleach to the water and mix them. 

Put on some gloves and apply the bleach solution to the caulk, scrubbing it with an old toothbrush. 

The discoloration should begin to fade with the action of the bleach. If it’s stubborn, leave an old rag soaked in the bleach solution wrapped around the base of the toilet covering the caulk.

Then try scrubbing the caulk again after twenty minutes. 

How To Apply Caulk Around Toilets?

The brown caulk is a sign that there is a leak in the toilet and this needs to be fixed before you fix the caulk. 

Turn Off Water Supply

Before you can do any work you’ll need to drain the toilet. First turn off the water supply. This will be at the rear of the toilet and is normally a football shaped valve. Turn it fully clockwise. 

Now flush the toilet to empty the cistern. If you have successfully shut off the water you won’t hear the cistern refill. 

You’ll also have to remove all the water out of the toilet as you’re going to have to uninstall it. Use a plunger and push the remaining water out of the toilet.

Alternatively you can sponge or siphon the water out. 

Caulk Around Toilet Turning Brown (1)

Get Access To Wax Ring

Undo the two screws at the base of the toilet and keep them safe. If the caulk is still intact in some places you’ll have to run a blade around it to break the seal in order to get the toilet off. 

Now lift off the toilet, and you’ll see the wax ring. Examine it for damage. This should be obvious if the caulk has already started to turn brown, chances are the ring has been deteriorating for a while.  

This is also a good opportunity to check the floor for water damage particularly if it’s a wooden floor. If there is damage this will need to be fixed before replacing the toilet. 

Replace Wax Ring

If you already have a new wax ring then simply swap the old one out for the replacement ensuring that it’s a good fit. 

Re-fit Toilet

You can now re-fit the toilet. Set it in place and re-fix the screws in the base making sure that there’s no movement. 

Re-caulk Around Base Of Toilet

When you are happy with the position of the toilet and that it is securely in place you can re-caulk around the base. It’s best to use 100% silicone caulk for this job. 

To Caulk Or Not To Caulk?

There is some debate about whether it is a good idea to caulk around a toilet. To follow code all plumbing fixtures should have a water-tight seal between them and the wall or floor

Reasons To Caulk

One of the main reasons for caulking a toilet base is to prevent water getting underneath the toilet. This could be from mopping the floor, splashes from the bathtub or water coming from a shower curtain. 

This water can cause wooden sub flooring to rot and require a major remodel of the bathroom.

Although you may have a tiled floor under the toilet it isn’t sealed around the toilet flange and water ingress is possible. 

Another very valid reason for caulking a toilet base is to prevent movement of the toilet. The caulk holds the toilet firmly in place.

This in turn stops the toilet flange seal from moving and becoming weakened. This is what can lead to the seal failing and a leak developing. 

Reasons Not To Caulk

Those who argue against caulking a toilet base cite the fact that if the toilet leaks and is caulked you will not see evidence of the leak on the floor.

Leaving an inch gap at the rear of the toilet will accomplish the same thing and still protect the majority of the toilet base. 

Final Thoughts

Caulk that has turned brown is normally a sign of a leaking toilet. So you will need to replace both the wax ring or seal on your toilet and replace the caulk.