Water in the Garage: Causes, Cleanup and Prevention in Arizona
Water in an Arizona garage usually comes from monsoon runoff under the door, a leaking water heater, a water softener or RO system, a failed washer hose or a broken irrigation line nearby. A wet garage floor is easy to mop, but water can wick into the drywall, the shared house wall and stored boxes. Stop the source, move items off the floor and dry the walls, not just the slab.
In many Arizona homes, the garage holds the water heater, the water softener, the washer and a lot of cardboard boxes. It also sits lower than the house on many lots, so monsoon runoff from the driveway can run straight in under the door. A wet garage floor looks harmless on bare concrete. The trouble starts when water wicks into the drywall, the shared wall with the house and everything stored on the floor.
If a pipe burst in the garage wall or ceiling, see our burst pipe repair Tucson and Valley service for what drying and repair involve.
Reading this with water on the floor? Get help first.
Need Help Now? Tap Here(833) 937-0179Why is there water in my garage?
Six sources cause most garage water calls. The pattern of the water tells you which one: where it starts, whether it is clean or muddy and whether it shows up during a storm or on a dry day.
| Source | Clue |
|---|---|
| Monsoon runoff | Muddy water fanning in from the door during a storm |
| Water heater | Clean water pooling around the tank or drain pan |
| Softener or RO system | Water near the softener, brine tank or drain line |
| Washer hoses | Water behind the washer after a load |
| Irrigation or yard line | Water seeping up at the slab edge on a dry day |
| AC condensate line | Drip near the air handler or along a wall in summer |
For appliance sources, see our guides to water heater and AC leaks and softener and RO leaks.
How do I clean up water in the garage safely?
Turn off power to anything sitting in water first. If the water heater is leaking, shut its cold supply valve and turn off the gas or breaker. Then remove the water, move belongings and get air moving. Treat muddy monsoon runoff as dirty water, since it can carry soil, oil and debris.
- Make it safe. Unplug or switch off power to wet outlets, tools and freezers.
- Stop the source. Close the water heater or softener valve, or the main shut-off.
- Remove water with a squeegee toward the door, or a wet vac.
- Lift and sort. Move boxes and items off the floor. Wet cardboard should go.
- Check the walls. Look at the bottom of the drywall, especially the wall shared with the house.
- Dry it out. Open the garage door on a dry day and run fans and a dehumidifier.
Can garage water damage the house?
Yes. The wall between the garage and the house is often drywall on both sides. Water that wicks up the garage side can wet the bottom plate and the drywall inside, behind a laundry room or kitchen. Water can also run under the door threshold into the house. Watch for swollen baseboards and a musty smell in rooms next to the garage.
Our guide to swollen baseboards explains what that sign means. If the shared wall stays damp more than a day or two, mold can start inside it, and water damage mold removal may be needed.
How do I keep monsoon water out of my garage?
Check the driveway slope and the gap under the door before the season starts in mid-June. Replace a cracked or flattened door seal, add a threshold seal on the floor, keep the gutters and downspouts clear and pointed away from the driveway, and keep sandbags handy if your lot sits low. The NWS Phoenix monsoon page posts outlooks and safety tips.
Our monsoon water under the door guide covers front and patio doors too.
When should I call a professional?
Call if water reached the drywall or the house, if the source was a burst line or water heater that ran for hours, if the water was muddy storm runoff that soaked stored items or walls, or if you smell mustiness days later. A crew can measure moisture inside the walls and dry them before mold starts.
We help homeowners across the Valley and Pinal County, from Queen Creek and San Tan Valley to Casa Grande. For homes in and around Florence, see our page on water damage restoration Florence AZ.
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Get Expert Help 24/7(833) 937-0179Frequently asked questions
Is water in the garage covered by insurance?
Sudden leaks from a water heater or pipe are often covered. Flood water from outside is usually not covered by a standard homeowners policy. Check your policy.
How long does it take to dry a garage?
A bare concrete floor dries in hours to a day. Wet drywall and stored items can take several days with fans and dehumidifiers.
Can I just mop up the water and close the door?
If only the slab got wet, often yes. If water touched the drywall, check it with a moisture meter or watch for swelling and smell.
Why does my garage floor get wet on dry days?
Look for a leaking water heater, softener or washer, or a broken irrigation or water line near the slab edge.
About the author
Noah Miller founded AZ Water Damage Help in Queen Creek to give Arizona homeowners fast, honest water damage help. He writes and updates these guides using public guidance from the EPA, the IICRC, the National Weather Service and Arizona state agencies. More about Noah.