Under the floor
Leaks Under the House: Boise Crawl Spaces
A big share of Boise houses, from Bench ranches to North End bungalows, sit over a crawl space. It hides plumbing well, which is the problem: a leak can run for weeks before anything shows upstairs.
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.
What tells you something is wet under there
A musty or earthy smell inside the house is usually first. Then floors that feel cool and damp, or soft near a bathroom. Insulation hanging down where you can see it from the hatch. More gnats or mosquitoes than usual. Condensation on ductwork. And a water bill that rises and stays up. Signs of a crawl space leak
Plumbing leak, groundwater or irrigation?
Not all water under a house comes from the pipes. If dampness shows up after rain or during irrigation season and the meter is perfectly still with everything off, it's probably groundwater or yard water. If the meter is moving, it's household plumbing. A sewage smell means a drain line, which is a different repair.
Boise's irrigation season soaks yards from spring into fall. Worth ruling out first: sprinkler heads aimed at the foundation, or a downspout dumping water right beside a vent.
Freeze damage that shows up in spring
Lines near foundation vents and along exterior walls are the first to freeze in a cold snap. The crack may not leak until the line thaws, or until spring brings heavier use. Heat tape that quietly failed is another common story. If your meter started moving after a cold spell, look here first. Pipes leaking after a freeze
How a crawl-space leak gets found
The technician goes in with a light, a moisture meter and a thermal camera, and checks under bathrooms, the kitchen and the water heater first. Sections of pipe can be pressure-tested to see which one is losing water. Where insulation hides the pipe, acoustic gear can pick up a hissing line.
Meter moving with every tap shut?
Short pause, then a person.
Safety before you go in yourself
If water is spraying, close the house shutoff before anything else. Don't go in if there's standing water near wiring, if you smell gas, or if the space is too tight to turn around in. A quick look from the hatch with a flashlight is usually enough to tell whether something is wrong.
After the repair
Wet insulation and vapor barrier usually need to be dried or replaced, and standing water pumped out. That's water damage work, often a separate company. Afterwards, heat tape or insulation on lines near the vents helps keep the same thing from happening next winter.
Before you hire anyone
Ask whether they go into the crawl space themselves and what they look for. Ask how locating and repair are billed, and 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 crawl space leaks
Should crawl space vents be closed in winter?
Many Boise homeowners close or cover them during deep cold to keep lines from freezing, then open them again in spring. What's right depends on how your crawl space is built, so ask.
How do I know if it's a sewer leak?
A sewage smell, or wet soil under a toilet or drain line, points to a drain. Clear water with no smell points to supply plumbing.
Is standing water in a crawl space always a leak?
No. Groundwater and yard water can get in too, especially during irrigation season. A meter check tells you whether household plumbing is involved.
Can a crawl space leak raise my sewer charge?
Yes, if it runs between October and April, because Boise sets the sewer charge from those meter readings. See the leak adjustment post for what the city asks for.
Related: wall and ceiling leaks · high water bill checks · Boise Bench · North End · Boise leak adjustment