Dripping faucets, water under the sink, ceiling stains, slab leaks: how to spot a leak early and what to do the moment you find one.
Usually it is a worn washer, cartridge, or O-ring.
What to do next: Turn off the shutoff valves under the sink, then identify the faucet brand if you can. For a single-handle faucet, the cartridge is often the part to replace. For older two-handle faucets, washers or stems may be the issue. If the shutoffs do not fully stop the water, call a plumber before taking the faucet apart.
Read the full guide →It could be the trap, faucet, supply line, disposal, or drain connection.
What to do next: Dry the cabinet completely, then run cold water, hot water, the sprayer, and the disposal one at a time while watching with a flashlight. Put a dry paper towel under each joint to spot the first drip. If it is from a supply line, shut that valve off. If it is from a drain slip nut, you may be able to gently tighten it by hand or replace the washer.
Shut off the main water valve first. Everything else comes second.
What to do next: Close the main shutoff, open a low faucet to drain pressure, and move valuables away from the water. If water is near outlets, appliances, or the breaker panel, stay clear and shut off power only if it is safe. Call a plumber for the repair and consider a water mitigation company if flooring, ceilings, or walls are soaked.
Read the full guide →Most often the wax ring failed or the toilet is loose.
What to do next: Stop using that toilet until it is fixed, because the leak may be dirty water and can rot the floor. Try gently tightening the closet bolts, but do not crank them or you can crack the toilet. If it still leaks, the toilet needs to be pulled and reset with a new wax ring or seal, and the flange should be inspected.
Treat it like an active leak until proven otherwise.
What to do next: Shut off water to nearby fixtures or the whole house if you cannot identify the source. Look above the leak for a bathroom, laundry, water heater, AC drain, or roof area. If the ceiling is bulging, place a bucket below and carefully poke a small drain hole with eye protection so it does not collapse suddenly. Call help quickly.
Watch the water meter when everything is off.
What to do next: Turn off every faucet, appliance, and irrigation zone, then check the water meter. If the leak indicator moves or the numbers keep changing, water is flowing somewhere. Also look for musty smells, warm floor spots, peeling paint, soft flooring, or a high bill. A plumber can pressure test lines or use leak detection equipment if the meter suggests a hidden leak.
Sometimes, but water damage gets expensive fast.
What to do next: If you can isolate it by closing a fixture shutoff, do that and schedule a repair. If the leak is inside a wall, ceiling, floor, or from a water heater tank, do not wait. Take photos, dry the area, and check again after an hour. Small steady leaks can ruin cabinets, subfloors, drywall, and framing before they look serious.
A few drips can be trapped water, but steady dripping points to the valve.
What to do next: If it stops after a minute or two, the showerhead may just be draining. If it keeps dripping, the cartridge or valve stem is likely not sealing. Turn off the bathroom water if you have access, or the whole house if not, then replace the cartridge with the correct model. If the cartridge is stuck, call a plumber rather than breaking the valve in the wall.
It may need a washer, packing repair, or full hose bib replacement.
What to do next: If it leaks from the handle, snug the packing nut slightly. If it leaks from the spout, the washer may be worn. If water shows up inside the wall or basement when you use it, shut it off immediately, because a frost-damaged pipe may be split. Remove hoses before freezes to help prevent this.
Only on threaded fittings, and only when threads are the problem.
What to do next: Use PTFE tape on tapered pipe threads, not on compression fittings, supply line gaskets, slip nuts, or faucet connections. If a connection seals with a rubber washer, replace the washer or supply line instead. If you are tempted to wrap tape around the outside of a leak, that is only a temporary bandage and not a real repair.
The hose washer may be bad, or the hose itself may be failing.
What to do next: Turn off both washer valves, then inspect the hoses for bulges, cracks, rusted ends, or damp spots. Replace rubber hoses with braided stainless washer hoses and new washers. If the valve drips when turned off, the valve itself needs repair or replacement before it becomes an emergency.
Small plastic fridge lines and saddle valves are common leak points.
What to do next: Pull the fridge out gently and look for water at the line, filter housing, and shutoff connection. Shut off the small valve if you can. If it uses a clamp-on saddle valve, consider replacing it with a proper shutoff valve and braided or approved tubing. Fridge leaks often hide under flooring, so dry it fast.
It could be a plumbing leak, roof leak, condensation, or AC drain issue.
What to do next: Note whether the stain grows after rain, after using a fixture, or all the time. Use a moisture meter if you have one, or tape a dry paper towel to the area and check later. If the wall is soft, smells musty, or the stain is spreading, call a plumber or leak detection pro. Do not just paint over it.
Warm floor spots, meter movement, low pressure, wet flooring, or unexplained bills.
What to do next: Turn off all fixtures and check the meter. If it still moves, then shut off the water heater cold inlet. If the meter stops, the leak may be on the hot side. Slab leaks usually need professional leak detection, not guessing, because breaking the wrong spot in concrete is expensive.
Read the full guide →The packing seal around the stem is worn or dry.
What to do next: Try gently tightening the packing nut behind the handle by a small amount. If that stops it, good. If it keeps leaking, or if the valve does not fully shut off water, replace it. For old multi-turn valves, upgrading to a quarter-turn valve is usually worth it.
The leak may be from the sink flange, dishwasher hose, drain outlet, or disposal body.
What to do next: Dry everything, then run water and watch from above and below. A leak at the top flange may need the disposal removed and resealed. A leak from a side connection may need a gasket or clamp. If water comes from the bottom of the disposal body, the internal seal has failed and replacement is usually the right move.
The tub drain, overflow gasket, or caulk line may be leaking.
What to do next: Fill the tub below the overflow and watch below. Then fill it above the overflow and test again. If it leaks only when the water reaches the overflow, replace the overflow gasket. If it leaks during draining, suspect the tub shoe or drain piping. If it leaks only during showers, check caulk and the shower valve trim.
Look for soggy spots, sunken soil, and a water meter that moves when zones are off.
What to do next: Shut off the irrigation isolation valve if you have one, then see if the meter stops moving. Run each zone briefly and look for low heads, bubbling soil, or unusually green patches. Irrigation leaks are often outside plumbing scope depending on your area, so you may need an irrigation contractor rather than an indoor plumber.
Same-day leak-detection availability across Austin, with acoustic and camera tools used before the problem becomes visible damage.
