Toilet Rocking Back and Forth - What's Causing It?
A rocking toilet can be an annoying and potentially hazardous issue in any home. If your toilet rocks or wobbles when you sit on it or push down on the tank, it likely indicates a problem with the mounting between the toilet and floor.
Ignoring a rocking toilet can eventually lead to leaks, water damage, and even injury. That's why it's important to diagnose and repair a loose toilet as soon as you notice movement.
Common Causes of Toilet Rocking
There are a few common culprits behind a toilet that rocks back and forth:
- Loose mounting bolts under the toilet
- Worn out toilet mounting hardware like bolts, washers, and nuts
- Uneven bathroom flooring under the toilet
- Clogged drain pipe causing blockages
Loose Mounting Bolts
The most typical reason for a rocking toilet is loose mounting bolts under the base of the toilet. Over time, these bolts can gradually loosen from repeated use and force on the toilet. This allows movement between the floor flange and toilet.
Loose bolts are often caused by corrosion from water exposure or using low quality hardware. Periodically checking and tightening the mounting bolts can help prevent loosening.
Worn Out Toilet Mounting Hardware
If your home is older, the original toilet mounting hardware may be brittle or corroded. Metal washers, nuts, and bolts degrade over time, especially from moisture. Replacing degraded mounting hardware with new bolts, washers, and nuts can permanently fix a loose, rocking toilet.
Uneven Subfloor Surface
An uneven floor or subflooring surface under the toilet can also lead to rocking and wobbling. If the toilet mounting surface is not level, the toilet will teeter and rock. Using shims during installation can level the toilet, but uneven floors may need repair.
Clogged Drain Pipes
A blocked drain pipe can also sometimes cause a toilet to rock. Waste and debris causes blockages in drain pipes connected to the toilet flange. This puts added lateral pressure on the toilet as waste tries to pass through a narrowed pipe.
Clearing clogged drains and removing obstructions can help stabilize a toilet suffering from drainage issues.
Diagnosing a Loose Toilet
Finding the cause of a loose toilet requires some simple diagnostic tests:
- Visually inspect the toilet base for loose mounting bolts or cracks
- Rock the toilet to check for floor unevenness under the base
- Plunge the toilet while rocking it to check for drain blockages
Loose mounting bolts will be visible underneath the toilet between the base and floor. Cracked porcelain also indicates the toilet is insecurely anchored.
Checking if the floor is uneven under the toilet helps determine if subfloor issues are the cause. Drain clogs can be detected by plunging while rocking.
When to Call a Professional
If you are uncomfortable performing the repairs or unable to determine the cause, call a professional plumber. They have the expertise to accurately troubleshoot and fix a rocking toilet.
Tightening the Toilet Mounting Bolts
For a toilet rocking due to loose mounting bolts, here's how to tighten them:
- Turn off the toilet water supply and flush to empty the tank
- Access the mounting bolts through the access panel behind the toilet base
- Evenly tighten the nuts in a cross pattern with a wrench
Avoid over-tightening the nuts to prevent cracking the porcelain. The bolts should be snug enough to minimize rocking while still allowing some slight wiggle room.
Tips for Proper Bolt Tightening
- Use a wrench with enough leverage for tightening
- Replace corroded bolts and washers
- Check bolt tightness twice a year
Periodically checking bolt tightness prevents loosening over time. This quick fix can stabilize a rocking toilet.
Replacing Toilet Mounting Hardware
For corroded, damaged, or broken mounting hardware, a full replacement is required:
- Completely remove old bolts, washers, nuts, and wax ring
- Install new wax sealing ring on toilet flange
- Insert new bolts through toilet base holes into flange
- Attach washers and nuts underneath toilet
- Tighten nuts evenly to secure toilet firmly
High quality brass mounting bolts and stainless steel washers provide the most durable toilet hardware. Follow the wax ring instructions to ensure a watertight sealing connection.
Hiring a Plumber
Some key times to hire a plumber for this toilet repair job include:
- Bolts are rusted and cannot be removed
- Porcelain is cracked or toilet is severely unstable
- The floor flange needs replacement
- You want a professional installation
Fixing Uneven Floors Under the Toilet
An unlevel floor under the toilet can cause rocking. Using shims is an easy fix:
- Lift toilet and place shims under uneven spots
- Replace toilet on top of level shims
- Retighten mounting bolts to secure
For more severe subfloor unevenness, the floor may need leveling compound applied or the subfloor may require replacement.
Preventing Floor Unevenness
Some tips to prevent toilet rocking from floor imperfections:
- Check for level floor prior to new toilet installation
- Monitor existing floors for settling or movement
- Replace water damaged or warped subfloor areas
Unclogging Blocked Drain Pipes
If plunging and rocking points to a clog, try snaking the drain pipe. Insert a drain auger to break up and clear obstructions.
For severe clogs, the toilet may need removal to access and inspect the drainpipe. Alternatively, a plumber has camera tools to diagnose drain clogs.
Preventing Drain Clogs
Habits to avoid clogged drain pipes leading to toilet rocking:
- Avoid flushing anything besides toilet paper
- Don't pour fats or oils down the drain
- Use a drain strainer to catch hair and debris
Preventing a Toilet From Rocking
Stay ahead of a loose, rocking toilet with these proactive measures:
- Inspect the toilet mounting bolts twice per year and tighten if needed
- Check for subfloor levelness and repair uneven spots
- Clear drain clogs quickly before they worsen
- Teach household members to only flush toilet paper
Catching and fixing toilet instability early prevents water damage, leaks, and injury.