Knocking Sounds in Plumbing: A Sign You Shouldn't Ignore
A knocking or banging sound when the shower is running might seem like a harmless quirk—but it's often a warning sign of an underlying plumbing issue. Whether you're purchasing a brand-new home or living in an older property, noises coming from your plumbing system should never be ignored.
This common phenomenon—often described as a "knock," "thump," or "hammering" sound—can indicate problems that could lead to leaks, damage to your pipes, or even costly repairs if left unaddressed.
What Causes the Knocking Sound?
One of the most common causes of this issue is a condition called water hammer. Water hammer occurs when water abruptly stops or changes direction, such as when a valve is closed suddenly. The momentum of the water creates a shockwave that reverberates through the plumbing system, leading to a loud banging or knocking sound.
Other possible causes include:
Loose or unsecured pipes behind walls
Excessively high water pressure
Worn-out or faulty plumbing valves
Waterlogged air chambers in the plumbing system
Improper installation of fixtures
While some of these issues are simple to fix, others require professional assessment and repair. The key is identifying the source early—before damage occurs.
Why It's a Concern During a Home Inspection
During a home inspection, strange sounds—like knocking pipes—can raise a red flag. Certified inspectors are trained to observe and report not only visual defects but also audible clues that suggest problems hidden behind walls or ceilings. Noises like these often point to wear-and-tear, installation defects, or deferred maintenance.
For prospective homebuyers, identifying issues like water hammer or loose piping during an inspection is essential. These are not cosmetic problems; they can lead to long-term issues such as pipe leaks, wall damage, or mold growth if water escapes behind finished surfaces.
Even in newer homes, improper pipe installation or poor pressure regulation can result in this kind of plumbing noise. A home inspection helps verify that everything—even what's out of sight—is in proper working order.
The Role of a Home Inspector
A home inspector's role is to observe, identify, and report findings that could affect the safety, function, or value of a property. When plumbing issues are present, such as strange knocking sounds, the inspector documents the condition, notes its potential implications, and recommends further evaluation by a licensed plumber if needed.
Home inspectors do not perform plumbing repairs—but they provide critical guidance that can help homeowners and buyers avoid expensive surprises down the road.
Why Every Home Should Be Inspected
Whether a home is five years old or brand-new, a comprehensive inspection can reveal a range of issues not obvious to the untrained eye. Plumbing is just one area where subtle signs—like knocking, dripping, or hissing—can indicate bigger problems.
LunsPro Inspection Group provides thorough residential and commercial home inspections in Charlotte, Greensboro, Raleigh, and surrounding areas. Our inspections include essential features such as:
Detailed, same-day digital reports
ASHI-certified and IRC-certified inspectors
Advanced tools like thermal imaging and drones
Add-on services like mold testing, radon testing, sewer scope inspections, and more
We help buyers make informed decisions and homeowners protect their investments—because what you can't see can still cost you.
What to Do If You Hear Plumbing Noises
If you hear a knocking sound from your shower or any plumbing fixture:
Schedule a home inspection to determine the source of the issue.
Check water pressure—excessive pressure often contributes to water hammer.
Consult a licensed plumber to make any needed repairs.
Review your inspection report for other signs of plumbing stress, such as corrosion, outdated materials, or improper installation.
Protecting Your Home with LunsPro
Strange noises in your home are never "normal"—they're often signs the house is trying to tell you something. With a qualified home inspector, you'll gain insight into these hidden issues before they become major repairs.
Whether you're buying, selling, or just maintaining your home, trust LunsPro Inspection Group for expert evaluation and peace of mind.