Emergency leak under the house: what to do first
If you hear water running under the floor or see it pouring out of the crawlspace vents, act fast.
- Close the main shutoff for the house.
- If you cannot find the shutoff, call our 24/7 line and stay on the phone while the dispatcher talks you through it.
- Do not go into a crawlspace with standing water if any wiring, a pump or a water heater is down there.
- Open a faucet at the lowest point of the house to drain the lines.
- Note where the sound or the water was coming from and tell the plumber.
Why crawlspace leaks go unnoticed
Under a pier and beam floor, a leak drips onto soil instead of a finished surface. The ground absorbs a lot of water before anything shows inside the house.
By the time the problem is noticed, the signs are usually indirect. A floor feels soft or bouncy, the house smells musty, the water bill climbs or the meter keeps turning with every tap closed.
Older houses near downtown Denton and many rural homes around Krum and Sanger are built this way, so the same signs show up across the area.
Signs of a leak under the house
One sign alone is a reason to check. Two or more together usually mean a leak.
- A water bill that rises without a change in how you use water.
- A musty or sewer smell coming up through the floor or vents.
- Soft, warped or cupped flooring, especially near a bathroom or kitchen.
- The sound of running water when every fixture is off.
- Wet soil or puddles at the crawlspace vents in dry weather.
- More insects or rodents than usual, drawn by the moisture.
Plumbing water or drainage water?
Not every wet crawlspace is a plumbing leak. The timing tells you which one it is.
| What you notice | Likely cause | Who fixes it |
|---|---|---|
| Water appears only after heavy rain. | Surface drainage or groundwater. | Grading, gutters or a sump pump. |
| Soil stays wet in dry weather. | Supply line leak. | A plumber. |
| Wet spot under a bathroom or kitchen. | Drain line or fixture connection. | A plumber. |
| Sewage smell with damp soil. | Cracked or separated drain line. | A plumber, then cleanup. |
What the plumber checks under the floor
The visit starts at the water meter. If it moves with every fixture closed, the leak is on the pressurized supply side. If it stays still, the plumber looks at the drain lines.
In the crawlspace, the plumber follows each line from where it enters the house, checking fittings, valves, supports and any section that sags or touches the soil. Drain lines are checked under each bathroom and the kitchen. Repairs inside the city are made to the 2021 IPC that Denton adopted in 2022.
Older homes may have galvanized supply pipe or cast iron drains under the floor. If the leak is one of several failing spots, the plumber explains whether a section repair or repiping makes more sense.
Frozen and split pipes under the house
Crawlspace pipes sit outside the heated part of the house, so they are among the first to freeze in a hard North Texas cold snap. A pipe can split while frozen and only start leaking once it thaws.
After a freeze, check the crawlspace and the water meter even if the taps run normally. A split found early is a smaller repair than one that runs for days. Our burst pipe repair line is open around the clock.
Insulating exposed pipe and closing crawlspace vents before a freeze lowers the risk. The plumber can point out the most exposed runs while under the house.
What crawlspace leak repair costs depend on
These factors decide most of the price.
- How easy the crawlspace is to get into and move around in.
- Whether the leak is on a supply line or a drain line.
- Pipe material and how many fittings need replacing.
- Whether more than one section of pipe is failing.
- Emergency timing versus a scheduled visit.
You hear the price before any work starts.
Crawlspace leak questions
Only if it is dry, there is no smell of sewage or gas and no wiring is in the water. Otherwise wait for the plumber, who has the lighting and protective gear for it.
Yes. Constant moisture under the house can rot subfloor and joists and invite mold. Fixing the leak early limits that damage.
A supply leak usually raises the bill and moves the meter. A drain leak does not, so smell and soft flooring are the better clues for that one.
Yes. Pipe insulation on exposed runs is a simple add-on during a repair visit, and it helps most before winter.