Behind drywall and plaster
Finding a Leak Inside a Wall or Ceiling
"There's a hole on the ceiling, and they come from a leak." Before anyone opens a wall, it helps to know which of three things is wet: a pressurized supply line, a drain, or the roof. They behave differently and they're fixed by different trades.
Your call is handed to a Boise plumbing office, and the hand-off can leave a short silence. Leave the call open until a person comes on.
Read the stain before anyone cuts
It grows whether or not anyone uses water. That points to a pressurized supply line, and the meter test will show it.
It shows up after showers or flushes. A drain, a tub overflow, a toilet wax ring or a shower valve.
It shows up after rain or snowmelt. The roof or the flashing. That's a roofer's job, not this line's.
A brown ring that has stayed the same size for months. Probably an old leak that's already been fixed.
Worth ruling out first: the fridge ice-maker line, the dishwasher supply, an attic water heater, or a furnace condensate line.
How the tech narrows it down without demolition
A moisture meter maps where the wet edge stops. A thermal camera shows the cold or warm shape of the water. Running one fixture at a time shows which one feeds the leak, and acoustic gear can find a hissing supply line inside a wall. Only then does a small inspection hole go in, at the mark.
Older North End and East End homes often have plaster and lath instead of drywall. It's harder to open and patch neatly, which makes pinpointing first worth even more there. North End homes
Second-floor bathrooms and attics
The usual spots are shower valve bodies, tub drains, toilet supply lines and wax rings, attic water heaters and their pans, and lines in exterior walls that froze during a cold snap. A line that split in the cold may not leak until it thaws. Pipes leaking after a freeze
Wet spot you can't trace?
Short pause, then a person.
After it's found
The plumbing gets repaired first. Then the wet drywall and insulation need to dry out or come out. That cleanup is a different trade, water damage work, and the plumber may point you to someone. Take photos before anything is removed if you plan to talk to your insurer.
Before you hire anyone
Ask what tools they'll use before opening anything, and how big an opening to expect. Ask how locating is billed and whether drywall patching is included. Confirm their Idaho license through DOPL and their insurance.
Your call is handed to a Boise plumbing office, and the hand-off can leave a short silence. Leave the call open until a person comes on.
Questions about wall and ceiling leaks
Can I just paint over the stain?
Only once you know the leak has stopped and the area is dry. Paint over an active leak and the stain comes back, and the damage keeps going underneath.
Is a small drip in the wall urgent?
A slow leak inside a wall soaks framing and insulation over time. It's worth finding soon, even if it isn't an emergency.
Do I need a roofer or a plumber?
If the stain only appears after rain or snowmelt, start with a roofer. If it grows when no one uses water, or after showers and flushes, it's plumbing.
Will mold start?
Materials that stay wet for days can grow mold. Getting the leak fixed and the area dried is what prevents it.
Related: slab leaks · crawl space leaks · high water bill checks · East End · how hidden leaks get found