Hidden Plumbing Issues That Fail Home Inspections in Older Marietta Homes
- Tyler Reynolds
- Jun 10
- 4 min read
For homeowners and buyers in Marietta, Atlanta, Roswell, Smyrna, Decatur, and surrounding suburbs
Why Hidden Plumbing Problems Matter in Marietta Homes
Whether you’re buying or selling a home in Marietta—where charming older homes are common—or across the Atlanta metro, few things doom a deal faster than hidden plumbing failures. These problems often lurk behind walls and under floors, silently causing damage and health risks until a professional inspector discovers them. If you’re relying on a quick peek at fixtures or faucets, you’re likely missing the bigger issues.
In Marietta and Cobb County neighborhoods like East Cobb, where homes built pre-1990 are prevalent, plumbing may use outdated materials (lead, galvanized steel, polybutylene, cast iron drainage pipes), or suffer from root intrusion, pipe bellies, or code violations. As experienced Marietta home inspectors, we’ve seen repair estimates in the thousands for issues discovered too late.
This blog dives deep into the 10 most common hidden plumbing issues that fail inspections in older Marietta homes—and how to prevent them from becoming deal killers.
1. Outdated or Hazardous Plumbing Materials
Galvanized Steel Pipes
Galvanized supply lines can corrode from the inside, reducing flow, discolored water, leaks, and lead to eventual failure .
Lead Pipes & Solder
Homes built before the 1980s may contain lead components, posing a serious health hazard and often requiring immediate replacement .
Polybutylene (PB) Pipes
Common in 1978–1995, PB pipes degrade with chlorine exposure. Even intact pipes are suspect—a significant risk during inspections .
2. Pipe Bellies and Sewer Line Sags
Over time, soil movement can cause sewer pipes to dip, creating “bellies” that trap waste and lead to backups. Inspectors can spot this issue via camera scoping and by analyzing drain performance .
3. Cast Iron or Orangeburg Drain Lines
Cast iron drains can deteriorate suddenly. Older homes may also have Orangeburg (tar paper–based) pipes that lack collapse resistance. Both types routinely fail modern inspections .
4. Hidden Leaks Behind Walls and Under Floorboards
Small but persistent leaks can rot framing, encourage mold growth, and lead to structural damage. Inspectors use moisture meters and sometimes thermal imaging to identify unexplained wet spots or musty odors.
5. Sewer Line Root Intrusion
Georgia’s tree-rich yards can allow invasive roots to infiltrate clay or cast-iron sewer lines, causing blockages and backups. Scoping often reveals these issues—ones not visible to the untrained eye .
6. Improper Vents or Missing Shut-Offs
Older homes lack code-required shut-off valves or backwater/venting systems. During inspections, our team notes missing main shutoffs and improper fittings, which need correction for compliance and safety .
7. Corrosion and Scale in Water Heaters
Water heaters older than 10–15 years commonly have failing TPR valves, rusting tanks, or corroded heating elements. These are flagged when discharge lines are lacking or non-functional .
8. DIY Plumbing Fixes That Don’t Hold Water
Inspected cases include unapproved materials (PVC glue on copper, duct tape joins) and improper reroutes. Anything that violates code or lacks permits will fail inspections and require correction.
9. Leaky or Missing Drain Pipe Traps
Code requires proper P-traps and venting. Older or DIY additions often lack traps or vent openings, causing sewer gas intrusion—a common fail point.
10. Corroded Water Service and Old Valves
Underground lines from the meter or house may be original cast iron or galvanized and corroded. Missing interior shut-offs—found in Reddit discussions—compromise serviceability and safety .
Georgia-Specific Plumbing Code Insights
Georgia has adopted the International Plumbing Code (2018 edition) with amendments, binding licensed plumbers and inspectors to modern standards . Older homes often fall short of current code, making pre-inspection upgrades essential to pass inspections and secure financing.
Real-Life Marietta Case Study
During a full inspection, a 1960s ranch near Marietta Square failed due to hidden polybutylene supply lines and a “belly” in its cast-iron sewer line. The seller agreed to a complete repipe with PEX and PVC, saving the deal and preventing a $10K insurance claim.
How Inspectors Detect Hidden Problems
Visual inspection inside cabinets, crawlspaces, and attics
Moisture meters for wall and floor checks
Video scoping of sewer lines
Assessing pipe type and age using presence & identification techniques
Running water tests to evaluate flow, pressure, and drainage
Preventative Steps for Homeowners & Sellers
Hire licensed plumbers familiar with Georgia’s plumbing codes.
Repurpose old pipes—galvanized, PB, lead, Orangeburg—with copper, PEX, or PVC.
Flush sewer line regularly and consider root barriers.
Install backflow prevention, shut-off valves, and proper venting.
Maintain water heaters and exchange TPR valves every 5 years.
Pre-listing inspection to uncover issues early—and avoid surprises.
FAQ Section
Why do older Marietta homes often fail plumbing inspections?
They typically still use outdated materials (like galvanized, lead, PB) and lack modern code compliance. Hidden leaks and sewer line issues are also common.
How much does a full plumbing inspection cost in Atlanta?
Expect $300–$500, including camera sewer scope and in-depth moisture detection.
Do I need to re-pipe the whole house?
Not always—but any outdated self that fails inspection needs replacement. A partial repipe may be enough depending on systems and materials.
Can DIY plumbing fixes pass inspection?
Only certified, code-compliant repairs with permits have a chance. Improper fixes are flagged and must be redone.
If you’re preparing to sell or buy in Marietta, don’t gamble on hidden plumbing issues. Schedule a thorough inspection—Reynolds Home and Property Solutions specializes in uncovering these silent issues in older homes. Visit reynoldshomeandpropertysolutions.com today to protect your investment.
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