Why does my outdoor hose bib drip after I turn it off?

The short answer

Your hose bib drips after you shut it off because the part inside that's supposed to seal (a rubber washer) has worn out, or because a hose left attached is trapping pressure and forcing water out the vacuum breaker on top.

Summer doesn't create the problem so much as expose it. You're using the faucet constantly, and a washer that limped through winter finally gives up.

Before you spend a dime, do one thing: unscrew the hose, open its nozzle to bleed the pressure, and watch the bib for a minute. If the drip stops, you were never dealing with a broken faucet at all.

What's actually going on inside

A hose bib is a simple valve. You turn the handle, a threaded stem screws down, and a rubber washer at the bottom presses against a metal seat to stop the flow. When it drips, one of those two surfaces isn't sealing.

The washer is the usual suspect. Rubber gets hard and flat with age and heat, and once it can't fully compress into the seat, you get that maddening drip that no amount of handle-cranking fixes.

The seat is the second suspect. On hard water, mineral scale and grit slowly pit and groove the metal. When the seat's rough, even a brand-new washer can't make a clean seal.

If the water shows up around the handle instead of the spout, that's the packing, a separate seal that keeps water from creeping up the stem. It usually just needs the nut snugged.

And if you've got a frost-free sillcock, remember the working parts are at the far inside end of that long tube. The stem you pull out will be 8 to 12 inches long, and the washer lives at the tip.

How to work through it, step by step

Start with the free diagnosis. Take the hose off, open its nozzle, and wait. Watch whether water drips from the spout end, weeps from the cap on top, or seeps around the handle.

Spout drip points to the washer or seat. Top cap weeping points to the vacuum breaker. Handle seepage points to packing. Nailing this down tells you exactly what to buy.

Next, find your shutoff. Some bibs have a small valve on the supply line inside the basement or crawlspace. Many frost-free ones don't, which means you're shutting off the house main.

Once the water's off, open the bib to drain it, then take it apart. Remove the packing nut, back the stem all the way out, and inspect the washer at the end.

Take the old stem to the store. Matching washer diameter and stem thread by eye is a good way to make two trips.

Reassemble, turn the water back on slowly, and check both the original drip and the packing nut area for any new weeping.

• Basic tools: adjustable wrench, flathead and Phillips screwdrivers, a washer assortment
• Optional: valve seat wrench if your seat is removable and pitted
• Optional: fresh graphite stem packing if the handle was the culprit

What it costs in 2026

That covers a washer assortment or packing kit, maybe a cheap seat wrench, and an adjustable wrench if you don't own one. The parts themselves are a few dollars; the rest is tools you'll keep.

The pro range is $150–$450. That's for a licensed plumber replacing a full hose bib or frost-free sillcock, including labor, the valve, and disposal.

Why the spread? Access and pipe type. A threaded bib on an accessible line is quick. A soldered copper sillcock, or one that requires opening the wall to reach the shank, takes longer and pushes toward the top of that range.

If the drip is just a stuck vacuum breaker, a replacement breaker cap or rebuild kit is $12 to $30 and often DIY, no plumber needed.

• Professional repair typically runs $150–$450. This is not a DIY job, so plan on hiring a pro.
• Vacuum breaker cap or rebuild kit (DIY): $12-$30
• Full hose bib replacement, threaded/accessible (pro): $150–$450
• Frost-free sillcock replacement, soldered or wall access (pro): $150–$450

Should you DIY this or call someone

The washer, packing, and vacuum breaker fixes are honest DIY jobs. If you can turn off the water, work a wrench, and match a part, you can handle those.

Where it crosses into pro territory: a damaged non-replaceable seat, a valve body that needs to be unsoldered and swapped, or any repair that means opening the wall to reach a frost-free shank.

Soldering near siding and framing is its own risk. If your bib connects to copper with a sweated joint, that's a torch job, and a licensed plumber does it faster and without setting your wall on fire.

We rate this symptom as not DIY-friendly overall, mostly because so many of these turn out to be frost-free units with no local shutoff and a seat that's already gone. The cheap fixes are real, but the failure mode that sends you to a plumber is common enough that you should know your limits before you start.

Can this wait, or do you fix it now?

A slow drip from the spout onto the ground is a moderate-urgency problem. It won't flood your house, but it's wasting water and slowly getting worse.

Fix it within a few weeks. A washer that's failing today will chew up the seat if you keep running the faucet against it, and that's the difference between a $10 part and a $400 replacement.

Move faster if you see water at the wall penetration, inside the crawlspace, or pooling against the foundation. That's a rot and structural risk, and it deserves attention in days.

And if it's the vacuum breaker leaking, that's a backflow protection issue for your drinking water, so don't leave it defeated or bypassed.

Why summer is when it shows up

Hose bibs fail on a use curve. All winter your outdoor faucet sits closed and untouched. Come May, you're watering the garden, filling the pool, rinsing the car, and cycling that valve dozens of times a week.

That heavy use finds every weak washer. A seal that technically held in April fails in July simply because it's finally being tested.

Warm weather also matters for freeze damage. A hairline crack from last winter can stay tight when the bib's cold and closed, then open slightly under warm summer expansion and full pressure.

And the hose habit is real. People leave hoses attached all summer with spray nozzles shut, which traps pressure and pushes water out the vacuum breaker. That's the single most common false alarm this time of year.

Older homes and hard water

If your house is 20-plus years old and you're on hard water, the valve seat is more likely to be your problem than the washer alone. Years of mineral scale slowly grind the sealing surface rough.

Homes built before frost-free sillcocks became standard often have short, basic bibs with a local shutoff nearby, which actually makes DIY easier. The tradeoff is those valves are older and more likely to have a worn seat.

Newer homes tend to have frost-free sillcocks. Easier on winter freezing, harder on repairs, since the working parts are deep in the wall and there's often no local shutoff.

Knowing which type you have before you start saves a lot of frustration once the water's already off.

Safety and don't-do-this notes

The vacuum breaker on top of the spout is there to protect your drinking water from contaminated hose water siphoning backward. Never remove or plug it just to stop a drip.

Resist the urge to over-tighten. Cranking the handle or the packing nut to force a seal is how a small repair becomes a stripped stem or a cracked nut.

If you shut off the house main, make sure everyone knows before they turn on a faucet or the water heater runs dry on a call for hot water.

Leave soldering to people who do it often. A torch near dry framing, insulation, and siding is a genuine fire risk, not just a plumbing one.

How we put this together

This guide reflects the way a field tech actually diagnoses a dripping hose bib: rule out the free stuff first, isolate where the water's coming from, then match the fix to the failed part.

Cost ranges are 2026 US estimates for typical single-family homes and vary by region, pipe type, and access. A soldered connection or a wall you have to open always pushes toward the high end.

The DIY-versus-pro lines are drawn conservatively on purpose. Plenty of these fixes are simple, but the failure that lands you at a plumber (a chewed seat or a buried frost-free shank) is common enough that we'd rather you know before you commit.