Why is a supply line leak found by the wet drywall?
A supply line inside a wall is hidden, so the first sign of a leak is the water that reaches the drywall, the baseboard or the floor. The readings show where the water is, and the wall is opened to find the line that is leaking.
Water inside a wall spreads along the framing and out at the lowest point. The wet area can be a long way from the failure, and it may show first at the baseboard or at the floor. The technician follows the wet area back toward the line rather than guessing where it is.
The line itself is not always visible when the wall is opened, because the water can run down the pipe and collect elsewhere. The readings and the path are used together to find the failure.
Should I try to fix the pipe myself?
A supply line repair should be done by a plumber, because the water is under pressure and a poor joint can fail again soon after. Shut off the water to the line and let the plumber decide how it is repaired.
Turning off the water at the shutoff valve is a safe step for a homeowner who can reach it. Opening a wall to look for the pipe is not, because the wall may hold wiring and the water may have made the materials weak.
The plumber checks the repair under pressure before the wall is closed, which is the safest way to know the joint will hold. Ask for that test to be done and for the result to be written in the record.
What is the wall like after the repair?
The wall is closed up after the pipe has been repaired and the cavity reads dry. The opening is patched by the trade that does that work, and the repaired section is recorded so that it can be found again if there is a problem.
The drywall that was removed is replaced in a patch the size of the opening, with the seams taped and finished. Paint is applied after the patch is dry and the finish has cured, and the new surface is checked for any stain that appears in the following weeks.
A wall that stains again after the repair means the leak may not be fully stopped or the cavity was closed too soon. The record of the readings is the first thing to check, and the plumber should be called back to look at the joint.
Does a supply line failure fall under my policy?
This site cannot say what a policy covers. A policy generally responds differently to a sudden failure of a pipe than to a leak that has been running for a long time, and the cause of the failure matters to the insurer. The record and the photographs are the evidence.
Photograph the wet area, the opening and the failed section before anything is repaired, if that can be done without delaying the shutoff. Keep any part of the pipe that was removed, because the insurer may want to see it.
The insurer decides what the policy pays. The technician records the source, the time the leak was found and the materials removed, and gives the record to you.
What does a supply line failure cost to fix?
This site does not publish prices. The cost moves with how much wall and floor must be opened, how much of the cavity is wet, how much material must be removed and how long the drying runs. The plumbing repair is a separate charge from the plumber.
The opening and the drying are scoped on site and approved before the work starts. A failure found quickly in one wall costs less to dry than one that has run into the floor or the ceiling below.
Ask for the drying scope in writing, with the wall, the materials and the goal listed. Keep the plumber's repair and the drywall patch as separate lines so each can be compared.