Why is my toilet loose at the base?

If your toilet is loose or rocking at the base, this is usually caused by either a loose toilet mounting bolt or an issue with the wax ring seal underneath the toilet. A loose toilet is something you’ll want to fix right away, as continued movement can damage the wax ring and cause leaks or loosen the bolts even further. Thankfully, tightening a loose toilet is an easy DIY project that can typically be done in under an hour.

What causes a loose toilet?

There are two main causes of a loose toilet at the base:

• Loose mounting bolts – The bolts that secure the toilet to the floor have become loose.
• Damaged wax ring – The wax ring that creates a seal between the toilet and drain pipe has become damaged or flattened.

Loose mounting bolts

Toilets are secured to the bathroom floor with metal bolts on either side. Over time, these bolts can slowly become loose due to movement and shifting of the toilet. If they become loose enough, you’ll notice the toilet rocking or wiggling at the base. Loose mounting bolts are the most common cause of a loose toilet.

Damaged wax ring

Underneath your toilet is a wax ring that creates a seal between the toilet and the drain pipe in the floor. This ring prevents water and sewer gases from leaking out. If the wax ring becomes flattened, compressed, or torn, it can allow movement of the toilet and break the water-tight seal. A damaged wax ring will usually cause leaks or rocking along with the looseness.

How to tighten a loose toilet

Fixing a loose toilet is a straightforward DIY repair. Here are the steps:

1. Turn off water supply – Locate the water shutoff valve behind or near the toilet and turn it clockwise to shut off water.
2. Flush toilet and empty tank – Flush to empty water in the bowl and use a sponge to soak up any remaining water.
3. Remove tank lid and set aside – The tank lid can simply be lifted off and set aside.
4. Disconnect supply line – The flexible supply line that runs from the valve to the toilet tank can be disconnected by unscrewing the nut.
5. Remove mounting bolts – Use an adjustable wrench or pliers to loosen and remove the nuts from the mounting bolts on each side.
6. Lift toilet and inspect wax ring – Carefully lift the toilet straight up and set it on its side on newspaper or a towel. Inspect the black wax ring underneath for any damage.
7. Clean area and re-install new wax ring – Use a plastic scraper to remove the old wax. Wipe the area clean and install a new wax ring centered over the flange.
8. Lower toilet back into place – Carefully set the toilet back onto the bolts and wax ring without shifting its position.
9. Reinstall bolts and nuts – Hand tighten the nuts back onto the mounting bolts evenly.
10. Connect supply line – Reconnect the water supply line to the fill valve and tighten by hand.
11. Turn on water – Turn the shutoff valve counterclockwise to turn the water back on and fill the tank.
12. Check for leaks and stability – Flush the toilet a few times and look for leaks at the base. Check that the toilet doesn’t rock by applying slight pressure.

Tightening and resecuring the mounting bolts is often all that’s needed. But replacing an old, flattened wax ring while you have the toilet up is a good idea to prevent future leaks. Take your time and don’t over-tighten the nuts or bolts to avoid cracking the porcelain. A properly tightened toilet shouldn’t rock or move at all.

When to call a plumber

While tightening a loose toilet is usually a quick DIY fix, there are some cases where you may need to call in a professional:

• The toilet is very heavy or awkward to lift – Very old or heavy toilets can be difficult to lift and maneuver safely.
• Bolts are corroded or won’t budge – Corroded, rusted, or stripped bolts that won’t tighten may need to be replaced.
• There are persistent leaks – A damaged flange or stubborn wax ring leak may require a plumber’s expertise.
• The toilet needs to be completely re-set – If the toilet is too far off the flange, a reset may be in order.
• You’re uncomfortable with the repair – If you aren’t experienced with toilet repairs, it’s best to call for help. Attempting a DIY without knowing what you’re doing can result in damage or injury.

A licensed, professional plumber has the skills and tools to safely lift and reset toilets, replace parts, and fix any underlying issues causing stubborn leaks or looseness. The cost is usually reasonable for a basic toilet tightening. Calling a pro is a good idea if the DIY route isn’t working.

Maintenance tips to prevent looseness

To help prevent your toilet from becoming loose again in the future:

• Avoid rocking or shifting when sitting – Don’t use the toilet as a chair or put excess side-to-side force on the bowl.
• Tighten bolts slightly if any wobble develops – Periodically check for looseness by wiggling the bowl and tighten bolts if needed.
• Consider replacing old mounting hardware – Corroded 50 year old bolts have a higher chance of loosening.
• Remodel carefully around the toilet – Don’t crack the wax seal by dragging heavy equipment over it.
• Replace the wax ring every 5-10 years – Periodic wax ring replacement helps prevent deterioration and leakage.
• Use extra thick wax rings – For heavier users, an extra thick ring provides added stability.

With proper installation and periodic maintenance, your toilet should remain securely fastened to the floor. But with age and use, some loosening can be expected. Catching and re-tightening loose bolts early is key before major damage occurs.

Why is a loose toilet a problem?

It’s important to fix a loose toilet right away because continued movement and rocking can lead to some problematic issues:

• Leaking – A loose toilet can break the wax ring seal and allow water to leak onto the floor, causing potential water damage.
• Splashing – A loose toilet may leak not only on the floor, but into the subfloor, eventually causing soft spots or wood rot.
• Gas escape – If the wax ring shifts, sewer gas can escape into the home.
• Cracks – Over time, shifting and rocking can crack the porcelain of the toilet.
• Tank failure – Excess movement can crack interior parts in the tank.
• Bolt damage – Movement can bend or damage mounting bolts, requiring replacement.
• Floor damage – A loose, leaking toilet can damage the flooring, underlayment, and subfloor.

Even minor looseness is undesirable, as the rocking and pressure can weaken the seal and hardware over time. The minor inconvenience of tightening the toilet now prevents much larger problems down the road.

Conclusion

If you notice your toilet rocks, wiggles, or shifts when you sit on it, take action to tighten it. In most cases, simply tightening the metal mounting bolts that secure the toilet to the floor will solve the problem. You may also need to replace an old wax ring seal during the process. With the proper DIY approach and maintenance, you can keep your toilet stable and avoid leaks or damage. But don’t hesitate to call a professional if the toilet is too heavy to lift, the bolts won’t tighten, or you can’t eliminate persistent leakage.