Dallas has some incredible older homes — Craftsman bungalows in Lakewood, mid-century ranches in Oak Cliff, Tudor revivals in Munger Place. The charm is undeniable, but the plumbing? That's another story. I've worked on homes in Dallas with every era of plumbing imaginable, and there are a handful of issues I see consistently in houses built before the 1980s.
1. Galvanized Steel Pipes
Homes built before 1960 often have galvanized steel supply lines. These pipes were hot-dip coated in zinc to prevent rust, but after 40–70 years, that zinc coating degrades and the interior surface builds up with scale and rust. The symptoms are: low water pressure throughout the house (not just one fixture), discolored water (rust-colored or brown tinge), and visible corrosion at joints and fittings. The fix is complete repiping — typically with copper or PEX. This is a significant project, but once done, you're set for another 50 years.
2. Cast Iron Sewer Lines
Homes from the 1920s through the 1970s typically have cast iron drain lines. Cast iron is actually excellent pipe material — it's quiet, durable, and long-lived. But after 50+ years, the interior develops heavy scale buildup (called tuberculation) that reduces flow, and joints can separate over time. If you're seeing slow drains throughout the house (not just one drain, which is likely a clog), that's often a sign of scale buildup or root intrusion in the main line. A camera inspection will tell you exactly what you're dealing with before committing to a repair.
3. Slab Leaks
Dallas homes built on post-tension concrete slabs (very common from the 1950s through the 1990s) are particularly susceptible to slab leaks. These occur when copper supply lines embedded in or under the concrete develop pinhole leaks from corrosion, electrolytic activity, or movement from Dallas's notorious expansive clay soil. Signs of a slab leak include: warm spots on the floor, unexplained increases in your water bill, the sound of water running when all fixtures are off, and cracks in your foundation or walls.
Slab leaks must be professionally diagnosed — don't let anyone open up your slab without a pressure test and ideally an acoustic or electronic leak detection first. Repair options range from direct access (opening the slab at the leak point), to rerouting the line through the attic or walls, to full repiping.
4. Polybutylene Pipe
Homes built between approximately 1978 and 1995 may have polybutylene (PB) pipe — a gray plastic pipe that was used as a cheap copper alternative during the copper shortage of the late 70s. Polybutylene was the subject of a massive class action lawsuit because the material degrades when exposed to chlorine in municipal water supplies, eventually causing catastrophic failures. If your home has gray plastic supply lines, get it repiped now — not when it fails, which is often sudden and severe.
How to identify polybutylene:
- Gray color (most commonly) — not to be confused with PVC which is white
- Labeled 'PB2110' on the pipe surface
- Commonly found at the water heater, under sinks, and at the main shutoff
5. Failing Wax Rings and Toilet Base Seals
Older toilets with original wax rings often develop slow leaks at the base that go undetected for years — saturating the subfloor and causing rot and mold. If you notice any of the following, pull the toilet and replace the wax ring: toilet that rocks or moves, soft flooring around the base of the toilet, staining or musty smell in the bathroom, or visible moisture at the base.
Joey's Pro Tip: If you're buying an older Dallas home, invest in a pre-purchase plumbing inspection — especially a sewer scope camera inspection. A $150–200 inspection can reveal a $15,000 slab leak or a collapsed sewer line before you close. I've saved clients from absolute nightmares with this single recommendation.
Got a plumbing concern in your older Dallas home? I'll give you an honest assessment and tell you exactly what you're dealing with. Call (214) 293-8857 or fill out the contact form.
