Buying a House in DeKalb? The Plumbing Checks Your Inspector Skips
Published 2026-03-19 · updated 2026-09-01 · by Alpha Leak Fix Pros, DeKalb, IL
A general home inspection is a visual survey. It is genuinely useful and it is not a plumbing investigation. Three of the most expensive plumbing problems a DeKalb house can have are invisible to it, and all three are findable before you close.
What a standard inspection does not cover
- The sewer lateral. Not inspected. Not even looked at. A failed clay lateral under mature trees is a five-figure repair and it is completely routine in the older parts of DeKalb and Sycamore.
- The buried water service line. Not inspected. Replacing one runs into thousands, and a galvanized service line that has started to fail will keep failing.
- Hidden leaks. An inspector notes visible staining. A slow leak behind a wall or under a slab produces nothing visible for months.
- Under-slab drainage. Basement bathroom and floor drain piping beneath the concrete is out of sight entirely.
The three checks worth paying for
1. A sewer camera inspection
Essential on anything built before roughly 1975 — which covers the near-campus neighborhoods, the Ellwood area, the older streets off Lincoln Highway and Fourth Street, and most of Sycamore’s historic district. Also worth doing on 2000s subdivisions like Devonaire Farms and the Rich Road developments, which are now old enough for settlement-related bellies and offsets to appear.
You are looking for: pipe material and age, root intrusion and where it enters, bellies and how much water they hold, offset joints, previous repairs and whether they were done properly, and the condition at the connection to the city main. You get video you can hand to your agent.
2. A meter isolation test
Fifteen minutes, and it tells you whether the house currently has a leak anywhere in its pressurised plumbing. Shut off every fixture, note the meter, wait, read again. Movement means water is escaping. Close the main shutoff and repeat to establish whether it is inside the house or in the buried service line.
If this test fails on a house you are buying, you want to know before closing, not after.
3. A supply piping identification
Ten minutes with a flashlight in the basement. What you find changes the numbers materially:
- Galvanized steel (dull grey, threaded fittings, magnetic): corroding internally. Budget for a repipe.
- Polybutylene (grey or blue flexible plastic, roughly 1978–1995): known failure history. Replace on principle.
- Copper: generally good. Look for green staining or patched sections, which indicate pinholes.
- CPVC (cream-coloured rigid plastic): gets brittle with age. Check fittings.
- PEX (flexible red, blue or white): modern and fine. Check that fittings look properly made.
The DeKalb-specific things to look at
The sump system
Nearly every house here has one. Check the pump’s age, whether there is a battery backup, where the discharge line ends (six to ten feet from the foundation, or it is recirculating), and whether the pit has a lid. Ask whether the basement has ever flooded. Then look at the basement walls for a horizontal efflorescence band, which answers the question regardless of what you were told.
The grade and the downspouts
Walk the perimeter. You want ground sloping away from the foundation, and downspouts discharging well clear of it. In DeKalb’s clay soil, a downspout dumping at the foundation puts hundreds of gallons into the backfill trench during one storm. This is the cheapest fix in the entire house and the most commonly neglected.
Freeze exposure
Look for supply lines running through exterior walls, rim joists, unheated garages and rooms above garages. Ask whether anything has frozen before. In a house with a bonus room over a garage, assume that floor cavity is effectively outdoors unless somebody has dealt with it.
The water heater
Find the manufacture date on the label. Over twelve years, budget for replacement. Check for a drip pan and a drain line, corrosion at the fittings, and whether the T&P discharge line is present and unobstructed.
The main shutoff valve
Find it and turn it. An old gate valve that will not close, or that turns freely without stopping the water, is a small repair now and a disaster during a burst.
Near-campus rental history
If the property has been a student rental, assume heavy fixture use and multiple generations of quick repairs by different hands. Mixed materials and improvised transitions are the norm. A pressure test is worth more here than anywhere.
Timing and negotiation
Do this during your inspection contingency period, not after. A camera inspection and a meter test together cost a small fraction of any one of the problems they find, and documented findings are far more persuasive in a price negotiation than a general inspector’s note recommending further evaluation.
If the seller declines access for a sewer camera on a pre-1975 house, that itself is information.
Quick answers
On anything over about fifteen years, yes. Subdivisions built in the 2000s are now at the age where settlement-related bellies and offset joints start appearing, and the ground under former farmland keeps consolidating for years. You get the video either way, which is worth having as a baseline.
Yes, and that is when they are most useful. We coordinate with the listing agent for access, work within the inspection contingency window, and provide documented findings you can use in negotiation.
The sewer camera on an older house, because it is the largest potential number and the one nobody else is looking at. On a newer house, the meter isolation test, because it tells you whether the home currently has a hidden leak.
More leak guides
The 30-minute meter test that tells you whether water is escaping, and whether it is inside the house or underground.
Where DeKalb pipes freeze, how to prevent it, and the first five minutes when one bursts.
Eight causes of a sudden bill spike, ordered from the cheapest fix to the most serious.
Leak line, answered 24 hours
(815) 849-0091Alpha Leak Fix Pros
1600 E Lincoln Hwy Ste D, DeKalb, IL 60115
One call does it. We work out what is likely wrong on the phone, quote before we come out, and book you in on the same call.