Spigot sprays water under siding

Quick Answer:

Turn off the water, open an access by removing the exterior trim or siding around the spigot, and inspect behind the wall to find the spray origin. Feel the insulation and sheathing for wet or rotten spots. Very briefly operate the valve to confirm the spray path, then replace the broken internal elbow or riser and repair any damaged sheathing before sealing the opening. If water is actively spraying behind the siding or you find soaked sheathing or insulation, call a professional.

Why This Happens

Outdoor spigots enter the wall via a riser and usually include an elbow or swivel fitting where the pipe changes direction. If that internal elbow or the riser breaks, water can spray into the wall cavity when the faucet is used. Over time freeze/thaw, corrosion, or movement of the pipe can cause a crack or separation. Trapped water then soaks insulation and sheathing and can cause rot or mold.

If the faucet is low or near a deck, you might also be dealing with a Leak under deck from outdoor faucet situation where the same internal break sends water to a different area instead of the yard.

Step-by-Step What to Do

1. Turn off the water

Locate and close the isolation valve for that spigot if you have one. If not, shut off the main water to the house before you open the wall.
Open the spigot to drain the line once the supply is off.

2. Remove exterior trim or siding to access behind the spigot

Carefully remove the escutcheon (trim plate) and any siding or a portion of it so you can see into the wall cavity around the spigot. Work slowly to avoid damaging siding you want to reuse.
Clear away insulation or housewrap as needed to get a good view.

3. Inspect insulation and sheathing for saturated spots and visible rot

Feel the insulation and the sheathing with gloved hands. Wet, heavy insulation or soft, discolored sheathing indicates water has been present and needs repair.
Look for mold odor, staining, or wood that crumbles. Make note of the full extent of damage before proceeding.

4. Operate the valve briefly to confirm the spray path

With the access open and everything clear, turn the water on very briefly to observe where the leak is spraying inside the cavity. Keep the valve open only long enough to confirm the path—seconds, not minutes.
Turn the water off again immediately and drain the line. Do not continue to run water while you plan repairs.

5. Replace the broken internal elbow or riser and repair damaged sheathing

Remove the damaged section of pipe, elbow, or riser inside the wall. Install an appropriate replacement fitting and secure it so it cannot move and stress the connection.
Cut out and replace any rotten sheathing and remove or replace heavily soaked insulation. Allow the cavity to dry before sealing.
Only after the pipe repair and sheathing/insulation repairs are complete should you re-seal or reinstall siding and trim.

6. Finish and test

Restore the water and test the spigot while watching the repair from the access. Check for leaks and ensure the area stays dry.
Replace housewrap/flashings and reinstall siding/trim, sealing properly to prevent future water entry.

What Not to Do

Avoid covering the area back up without accessing and repairing the internal break—hiding the problem will make damage worse and more expensive to fix later.
Do not ignore soaked sheathing or insulation; that material needs removal and repair to prevent rot and mold.
Call a pro when water is spraying behind siding or you detect interior sheathing or insulation damage rather than attempting complex structural or plumbing repairs beyond your skill level.

When to Call a Professional

When water is actively spraying inside the wall and you cannot stop it from the accessible shutoff.
If the sheathing is soft, widely rotten, or moldy—these require proper drying, replacement, and possibly mold remediation.
If the pipe repair requires soldering, invasive framing removal, or you’re unsure how to properly flash and seal the siding afterward.

Safety Notes

Always shut off the water before cutting into walls or removing fittings.
Wear gloves, eye protection, and a dust mask when touching wet insulation or rotten wood to limit exposure to mold and contaminants.
Watch for electrical wiring in the wall cavity; if water has reached wiring, turn off power to that area and call an electrician.

Common Homeowner Questions

Can I keep using the spigot until I fix the wall? — No. Shut the supply off until you locate and repair the internal break to avoid more damage.
Will I need to replace the siding after the repair? — Possibly; you may be able to reuse some trim, but damaged siding or flashing should be replaced for a proper seal.
Could this happen from winter damage? — Yes. Freezing can split internal elbows or risers; consider reading about Spigot leaks after winterization for winter-related causes and prevention.