6 Common Plumbing Problems in Older Homes and How to Solve Them

Whether you already chose an older home for the love of its historic appeal or you’re considering a fixer-upper that’s right in your budget, it’s good to know what to expect. Old houses come with their fair share of quirks, but hidden plumbing issues in old homes can be more dangerous than charming.

Use our guide to learn the signs of common plumbing issues that can impact older homes. Get familiar with plumbing questions to ask before you buy an older home and what to do about problems when you spot them. 

Plumbing Problems to Check for in Older Houses

Some plumbing problems make themselves obvious, but others require careful inspection.

1. Corroded Pipes

Signs of corroded pipes include:

• Yellow, green, or brown discolored water

• White, green, or red discoloration on pipes beneath your sink or in your basement

• A water meter that runs when no water is flowing

• Rising monthly water bills without increased usage

• Wet or sagging carpeting or flooring, a sign of leaks under your concrete foundation

If you see any of these signs, your pipes may be on the verge of leaking or bursting. If you experience extensive plumbing issues, have a local plumber replace all your supply lines at once. The average cost to replumb all supply lines in a home starts at about $1,200. Your pro can replace corroded pipes with flexible plastic or copper pipes. 

These signs aren’t the only things that can affect your pipes. With advances in building techniques, many plumbing materials have fallen out of use. In homes built before the 1990s, there’s a chance that the system contains one of these outdated types of plumbing pipes no longer approved by US building codes:

Lead

Lead is highly toxic in a number of ways, from causing aches, constipation, and fatigue to interfering with how brains function and develop, decreasing fertility, and leading to hypertension and anemia. Unlike most other toxins, our bodies have no ability to purge lead. Despite all these effects, our knowledge of lead’s toxicity is relatively recent.

That’s why, prior to the development of cast iron, applications for lead included sewer lines, water mains, and pipe fittings for its flexibility and durability. You can’t see, taste, or smell lead in drinking water, so the Centers for Disease Control and Prevention (CDC) recommends having your water tested by your water provider. If they tell you your home has lead service lines, ask if they offer removal programs.

Galvanized Steel

Galvanized pipes were used for water lines in homes built before the 1960s and featured a protective coating of zinc. As the zinc erodes, the metal can corrode, causing old pipes to clog with rust or break.

Polybutylene

Originally a replacement for copper water lines, this plastic piping reacts with oxidants in many public water systems, which causes flaking and cracking. Any home built in the 1980s or early 1990s, especially mobile homes, may have polybutylene pipes that need replacing before they fail.

2. Pipe Bellies in Main Drains

Many pipes are installed underneath homes, either buried in the ground or encased in the concrete slab of the foundation. These pipes can shift downward as houses settle gradually, creating negative slopes called pipe bellies that restrict water flow and cause pools that collect waste and sediment. These bellies eventually get stopped up and leak.

Bellies, or “sags,” are not a concern in a water main because the line is pressurized, but they are a concern in a main drain. A sag holds water and the low point creates a location for waste to hang out and eventually clog. It also attracts tree roots due to the standing water. 

Some common signs of pipe bellies include:

• Frequent clogging

• Slow draining fixtures

• Gurgling sounds

• Foul odors in the drain

To address pipe bellies, contact a professional plumber to run a sewer camera into the pipeline. This will help determine whether you have a pipe belly and how bad the damage is. If the camera reveals that you have a pipe belly, the plumber will most often repair it by replacing the affected section of the pipeline. They will cut away the damaged part and replace it with a new pipe. 

While a typical plumbing inspection costs between $100 and $200, a camera inspection can cost much more—upwards of $1,175.

3. Failing Sewer Lines

When buried sewer lines fail, they can back up into your home. Modern appliances force more water through sewer lines, so extensive remodeling in older homes may lead to the risk of sewer line failure. Sewer lines can also be damaged by shifting foundations or tree roots.

Signs of failing sewer lines include:

• Foul-smelling wastewater backing up into your home

• An egg-like or unpleasant smell in your home

• Multiple slow drains, which can indicate a partially blocked sewer line

• Unexplained puddles or soft spots in your yard when it hasn’t rained recently

If you’re experiencing foul-smelling wastewater in your home, call your local sewer service. They may not need to dig out the pipe to repair it, thanks to trenchless sewer replacement techniques that involve less labor and risk of damage to your home or landscaping.

Foul smells that appear without signs of water may indicate a sewer gas leak. Exposure to this gas is potentially harmful to your health and may be highly toxic even at low levels. These gasses are flammable and highly explosive, and health effects can include hydrogen sulfide poisoning or asphyxiation. Call a plumber immediately to determine the source. Just be ready to spend more: Emergency plumbers costs tend to run 1.5 to 3 times more than typical plumbing costs.

The most common suspects of a sewer gas leak are: 

• Dried-out pipes beneath the sinks of your home

• Disconnected pipes

• A damaged drain line

• A broken plumbing vent

• A cracked or crumbling wax seal

• A crack in the foundation

Once the plumber determines the cause of the gas leak, they will either repair the damage or replace the area entirely.

4. Outdated Fixtures and Connections

Photo: Tony Ruji / Adobe Stock

Part of the charm of a historic home is the many antique faucets and fixtures throughout. Sadly, though, these features won’t last forever. Corrosion and wear on hardware and connections can cause low water pressure and leaks, making water use in your home inconvenient. 

Many homeowners opt to deal with these inconveniences, but this is risky. Small leaks and minor issues left unattended can become more severe over time, potentially leading to more costly plumbing repairs and permanent water damage to your home.

Signs of outdated fixtures include:

• Broken knobs on sinks, tubs, or showers

• Leaks of any kind

• Restricted water flow

Preventative maintenance is key to avoiding hundreds or thousands of dollars in water damage repair costs. The best ways to stay on top of any plumbing issue is to:

• Check your fixtures for any cracks, leaks, or damage

• Check for any changes in water pressure

• Be on the lookout for excessive running or leaks in toilets

• Look for improper connections on your appliances

It’s also wise to have a plumber perform routine plumbing maintenance annually, as they will have the tools and training needed to find problems you may have missed.

5. Badly Executed Repairs

The older your home, the longer it’s had to experience problems. Even if you’re careful with your fixtures and plumbing, previous owners may not have been. Before you purchased the home, there may have been DIY repairs made by unqualified former homeowners or a general handyperson.

Some of these problems may include: 

• Unsecured pipes

• Improperly installed sink traps

• Unsafe water heaters

• Showers with improper slopes 

If you suspect your home may have any of these problems, contact a professional plumber to get a plumbing inspection. They will be able to determine if there are any improper repairs and rectify any of the common problems on this list.

6. Poor Draining

Pipe bellies may be the most common cause of slow draining pipes in an old home, but there are several reasons your sinks, showers, and other plumbing fixtures could be draining slowly.

Issues or clogs with the vent stack are possible, but more likely, decades of soap, scum, and other debris has caused clogs somewhere in your pipes. In homes surrounded by old trees, it’s also possible that root growth is also disturbing the pipes.

To determine why water is draining slowly, you’ll need to call in a plumber for a thorough inspection.

Why You Need a Professional Plumbing Inspection

If you currently live in, or are about to move into an older home, it’s important to have a professional plumbing inspection. The inspection will help determine if you have any of the problems listed above, and they’ll find any other problems that may go unnoticed otherwise. 

The cost of a plumbing inspection ranges from $100 to $1,375, with the average coming out to $575. While you may not want to shell out this initial cost, it can save you big time in the future.

During a plumbing inspection, the plumber will take a look at your water heater, exposed plumbing, fixtures, appliances, and insulation. They may use video cameras to inspect your pipes and drains for any damage or blockages. The plumber will also ensure that all permits are up to date and that the plumbing is up to code, so you can rest easy in your old home.

Questions to Ask the Plumber

Before hiring a plumber to inspect or repair pipes and fixtures in your old home, it’s important to ask a few questions. We recommend getting quotes from at least three plumbing companies to compare price, timeline, customer reviews, and the answers to these and any other questions you may have:

• Are you a licensed plumber, and will the professional who actually performs the work be licensed?

• Is your company insured?

• What permits are needed for this project, and who is responsible for obtaining them? If you get the permit for me, is that cost reflected in your estimate?

• When can you start the work, and how long will it take?

• What do I need to do to prepare my home ahead of the service? How long will the water and/or gas be shut off?

• Do you offer a warranty for your work?

• Do you have examples of past work and/or client testimonials to review?

• Are there common issues that arise during this kind of work, and how much do they impact the cost if so?

Nick P. Cellucci contributed to this piece.