Quick Answer:
If you see pressure swings while doing a routine inlet pressure check and worry a pressurized run is broken, stay calm. Record the exact pressure readings and any timing with slow drains or backups, inspect visible joints for hairline leaks, and run isolated flow tests on sections of the system. Those steps will tell you whether roots are finding their way in during pressure drops or whether the issue is elsewhere. If the pattern returns or you find new wet spots, give the plumber a pressure log so they can reproduce the event.
Why This Happens
Pipes under pressure can hide small leaks that only open or draw in soil when system pressure falls. Roots are attracted to moisture and tiny gaps; when pressure drops they can be pulled into hairline openings more easily. Seasonal changes, nearby trees, or a sudden loss of city pressure can cause brief pressure swings that encourage root intrusion. For more background on how systems react after interruptions, see the short guide on roots after a pressure drop and the related notes about roots after a city outage.
Step-by-Step What to Do
1. Record inlet pressure and note any correlations
- Use your pressure gauge at the same inlet point each time. Write down the reading, date, time, and what else happened (e.g., slow kitchen sink, toilet backup, city work notice).
- Log repeated readings for at least a few hours or during times you notice the problem. Short, time-stamped notes are very useful to a plumber.
2. Inspect visible joints and fittings
- Look at accessible pipe joints, cleanouts, and service connections. Use a flashlight and feel for dampness or green growth on the outside of fittings.
- Hairline leaks at a joint may only seep when pressure drops; those small wet traces or root threads near joints are a warning sign.
3. Test flow by isolating sections
- If your system has shutoff valves that isolate runs, close valves to isolate the suspect section, then run water elsewhere to create the pressure condition while watching the suspect run for new seepage or wet spots.
- Do tests in short intervals and keep notes: which valve you closed, how long you ran water, the inlet pressure reading before and after, and whether any ground became wet.
4. Prepare and share a pressure log
- Compile your readings and observations into a short log: time, inlet pressure, what you were doing in the house, and any drain issues or visible wet areas.
- Give the log to your plumber so they can replicate the pressure-change condition under controlled conditions and plan the right repair (relining, targeted excavation, or joint replacement).
What Not to Do
- Avoid repeatedly increasing household pressure with boosters to “force out” roots; that can stress joints and worsen infiltration. If pressure swings coincide with new leakage or backups, stop makeshift fixes and call a professional.
- Don’t dig around suspect pipes without confirmation—excavating based on guesswork can damage utilities and landscaping.
- Don’t use chemical root killers as a first step where structural leaks are possible; they may mask the problem or harm nearby plantings without fixing the entry point.
When to Call a Professional
- Call a plumber promptly if you find new wet spots, repeated backups, or if your recorded pressure log shows consistent swings tied to symptoms.
- Bring your pressure log to the appointment. A plumber can recreate the pressure event safely and inspect or camera the line to find root intrusion or failing joints.
- If you smell sewage, see persistent pooling, or have surging drains, arrange a professional visit right away—these are signs the problem is active and could worsen quickly.
Safety Notes
- Turn off water at main shutoff valves before working on pipes. If you are unsure which valve controls a section, stop and call a plumber.
- Avoid electrical hazards near wet spots. Keep power tools and extension cords away from standing water.
- Do not attempt major excavation without utility locates. Call your local utility notification service before digging.
Common Homeowner Questions
- Will roots always mean a full pipe replacement? Not always—small entry points can sometimes be repaired or relined, but a camera inspection will show the best option.
- How long should I log pressures before calling a plumber? A few days of time-stamped readings that show the pattern are helpful; call sooner if you see backups or visible leaks.
- Can I stop root intrusion by cutting the tree? Cutting a tree won’t remove established roots and may make conditions worse; consult a plumber and an arborist for coordinated action.
More in this topic
For more related fixes and similar symptoms, see Tree Root Intrusion Patterns.