How to Tell If Toilet Is Leaking Underneath

Does your bathroom double as a swimming pool? Probably not. You may not be able to do the backstroke, but there could be standing water around the toilet. It’s not much of a concern if you just jumped out of the shower soaking wet, but if there is constant dampness on the floor, it’s time to get to the bottom.

Identifying the source of a leak around your toilet will save you money in the long run. Check if your toilet is leaking underneath so a plumber can repair it before things get worse. Here is a checklist of telling if your toilet is leaking underneath:

Locate the toilet leak

Water has to come from somewhere, and in the bathroom, there are only so many water sources. Go on a water hunt and follow the trickle to find the leak.

First, you can start with the toilet tank and visually inspect it for cracks. Then check the water lines. If you come up dry, it is coming from the toilet’s base. Determining where the water is coming from will dictate how you fix it.

Loose tee-bolts

Now that you know where the water is coming from look at the tee bolts holding down the toilet to the floor. If they are loose, the toilet may be coming off its seal and leaking. Loose bolts cause movement and can crack the wax seal.

Get a wrench and tighten them back down, making sure not to crack the bowl. Wipe up all the water, and then give it a few flushes. If there is no more water, you are in the clear. If it’s still leaking, you need to make repairs.

Spongy floor

This is a tell-tale sign of a water leak at the toilet’s base. Over time leaking water can damage the subfloor and cause it to wear or rot. This water-logged surface will be spongy and cause your toilet to move around as you sit down. The toilet would be stationary and sturdy, so you have water underneath if you have a spongy floor around the base.

Foul odours

It isn’t potable when the water source is from underneath the toilet. This is the water that is being flushed down and with it is what you deposit in the bowl. When the dirty water soaks through, it will cause a foul smell in the bathroom, and no matter how much you clean and disinfect until the leak is repaired, the odour will persist.

Broken wax ring

The wax ring under your toilet is designed to last up to 30 years, but it can dry out and break over time. This ring makes a tight seal between the toilet base and the floor to prevent any leaks from spilling onto the floor.

A wobbly bowl is a sign of a damaged seal, and you can usually feel the difference between the wax ring giving way instead of the floor being spongy. This problem is not going away, so you will need to replace the ring.

Cracked toilet bowl

A cracked bowl may leak dirty water onto the floor without affecting the wax seal. It will, however, damage the subfloor over time. Inspect all around the bowl to see if there are any visible cracks. You can also put food colouring or dye into the bowl and watch for it to show up on the floor. Make sure not to flush so you know it is from a crack and not flushing.

Noticeable toilet stain

You may have had a leak under the toilet for a while without realizing it, and then a stain appears. This is a clear indication of a leak that is not new, and there will be damage to the subfloor. It’s important that you get this repaired soon as you don’t know the condition of the floor and if there is a mould issue.

Repair the toilet

Repairing a leaking toilet is going to take tools and know-how. You will have to remove and replace the toilet, change the wax seal, and even fix the subfloor. This is a dirty job because of the water contaminants, so rubber gloves are necessary. If the task is more than you can or want to handle, contact a qualified plumber to take over and get you up and running again.

Prevent the toilet leak

After you have your toilet fixed, it is better to go forward without recreating the same issue. Here are a few tips to prevent future leaks:

  • Fix small leaks as soon as you notice them before they get worse and do major damage.
  • Inspect your toilet base and components every six months.
  • Stay away from harsh drain cleaners as they can damage fixtures, pipes and connections. Use a natural DIY solution for clogs.
  • Don’t flush non-flushable items. These can cause a blockage which in turn creates pressure and possible leaks.