Buzz
While a rocking chair offers comfort and relaxation, a rocking toilet does quite the opposite. The unsettling sensation of the toilet shifting beneath you as you sit could point to a significant plumbing issue that needs immediate attention.
While DIY solutions exist for a wobbly toilet, simply securing it to the floor without diagnosing the root cause might conceal more severe problems. Mytour consulted three plumbers and a general contractor to explore common reasons for toilet instability, possible DIY fixes, and the importance of addressing the issue promptly.
What causes a toilet to wobble?
According to Roy Barnes, a seasoned plumber with nearly three decades of experience and co-owner of Service Force Plumbing in Rockville, Maryland, a secure connection between the toilet base and the sewer line relies on three critical components:
The flange: This wide ring sits atop the sewer line where it meets the floor, featuring bolt holes and ensuring a proper seal. "Over time, flanges can degrade and should be checked if issues arise," Barnes explains to Mytour.
The wax ring: This component forms an airtight and watertight seal between the toilet and the sewer drain, whether it's made of PVC or metal. The bolts at the toilet's base not only secure the toilet but also keep the wax ring tightly in place.
The base of the toilet: It must remain intact, free from cracks or wear caused by aging.
If any of these components fail, it can lead to a rocking or unstable toilet. Josh Rudin, a general contractor and owner of ASAP Restoration, a Phoenix-based company specializing in water, fire, and mold restoration, highlights some common causes of toilet instability:
Loose toilet bolts
Worn-out wax rings
Uneven flooring
Damaged or uneven sub-flooring
Loose flange fittings
Incorrect positioning
Cracks in the toilet base
While these issues can destabilize your toilet, the underlying cause—such as what led to loose bolts or a damaged wax ring—is equally important to identify.
Barnes notes that a frequent cause of these issues stems from poorly executed bathroom renovations, particularly when new flooring is installed. "Ensuring the sewer pipe's flange is level with the floor is crucial, but many flooring contractors overlook this," he states. "When the new floor is laid at the wrong height relative to the existing flange, the wax ring fails to create a proper seal upon toilet reinstallation."
Barnes explains that homeowners often remain unaware of this issue until their toilet begins to rock, sometimes months or even years after the renovation. It’s only when they call a plumber to address the instability that they discover the seal has been leaking all along, leading to substantial subfloor damage.
How to determine the cause of a wobbly toilet
Whether you plan to fix the rocking toilet yourself or hire a professional, identifying and noting specific signs can help pinpoint the root cause of the instability.
Kodi Wilson, a plumber, plumbing instructor, and campus director at National Technical Institute's Las Vegas branch, recommends beginning with a visual inspection of the bathroom to spot potential issues. "Many problems can be detected just by observing the toilet, and often multiple issues arise simultaneously depending on the underlying cause," he tells Mytour. "Is there evidence of a leak? Does the floor show damage? Are the nuts and bolts loose when touched?"
Wilson explains that water leaking from the toilet base often indicates multiple issues. "The best course of action is to remove the toilet and assess the extent of the damage," he advises.
Inspect your flooring for signs of damage. Wilson notes that warping, uneven surfaces, or cracked tiles typically result from two main causes: water damage or the natural settling and aging of the home. If such damage is evident, he recommends removing the toilet to investigate further.
If the bolts securing the toilet to the floor are loose, Wilson cautions against assuming that tightening them will resolve the issue. Instead, he advises checking for water damage immediately.
Barnes concurs, emphasizing that while tightening the bolts might stop the rocking, it’s risky to assume this is the only solution. "If the toilet has been unstable for some time, the constant movement could have damaged the wax ring seal, allowing water to leak unnoticed," he explains. "This hidden damage can worsen over time, and tightening the bolts might mask ongoing leaks that harm the subfloor and structural joists."
Beyond visual inspections, Rudin suggests using your sense of smell. "A faulty seal can allow sewer odors to escape, and the toilet's movement can exacerbate this issue," he says.
Why ignoring a rocking toilet is a bad idea
As experts point out, a wobbly toilet often signals more significant and costly underlying issues.
In the short term, a shaky toilet can cause leaks around its base, potentially damaging the floor and subfloor, explains Matt Kunz, president of Mr. Rooter Plumbing, a Neighborly subsidiary. It can also make using the toilet uncomfortable, unsettling, and even unsafe for household members and guests.
"Over time, continuous rocking can weaken the wax ring seal and the toilet's attachment to the floor, raising the risk of severe water damage," Kunz tells Mytour. "Fixing the problem quickly ensures a stable toilet, prevents structural harm, and maintains proper bathroom functionality."
Additionally, Wilson notes that water damage can also encourage mold growth, compounding the problem.
Rudin emphasizes that delaying repairs for water leaks and damage only worsens the situation, increasing both repair costs and the potential decline in your property's value.
How to repair a wobbly toilet
While DIY methods exist to stabilize a toilet, experts warn that these only address the rocking motion and not the root causes. "DIY fixes for a toilet base are rarely straightforward," says Rudin. "Most toilet repairs require two people due to the weight of the fixture, which can exceed 100 pounds depending on the model."
If you're certain of the cause and there's no water damage, Wilson notes two potential solutions. First, tighten the base bolts evenly, avoiding over-tightening to prevent cracking the porcelain. Second, if the floor has settled without water damage, shim the low side of the toilet and secure the bolts.
Barnes stresses the importance of checking the flange and wax ring for proper function before attempting repairs. "The connection between the flange, wax ring, and toilet works flawlessly when installed correctly," he explains. "If shimming is needed, it likely indicates improper installation or a failure in the setup."
When to contact a professional plumber
Addressing a rocking toilet is more complex than it appears. Due to the potential complications, hiring a plumber to assess the situation is often more cost-effective than facing expensive repairs for hidden issues later. As Barnes explains, "Properly installing a flange at the correct height and using a correctly sized wax ring is much cheaper than replacing subfloors, flooring, or even structural joists years later when extensive damage has occurred."
Attempting DIY repairs on a wobbly toilet could lead to further damage, increasing the overall repair costs. "This could result in thousands of dollars in additional damage over time," Rudin warns.
