Water on the Garage Floor in Arlington? 6 Places It Comes From

Water on a garage floor usually comes from 6 places: the car (AC drip or fluids), rain blowing under the door, the water heater, a water softener, a hose bib or pipe in the garage wall, or a supply line under the slab. Clear water that comes back on dry days with the car gone points to plumbing. Do a meter test, and if the dial moves, call (817) 285-5426.

Garage leaks are easy to ignore, but the water lines that feed the house often run through the garage wall or under the garage slab. Our leak detection company finds the source with acoustic gear before any concrete or drywall is opened.

How do you find which one it is?

Move the car out, dry the floor with a squeegee and towels, and check again after 6 to 12 hours of dry weather. If the floor stays dry, it was the car or rain. If the water comes back, look at where it starts. Water by the heater points to the tank. Water along a wall points to a pipe. A damp patch in the middle of the slab points to a line underneath.

What are the plumbing sources to check?

1. The water heater

Look at the drain pan, the relief valve pipe and the fittings on top. A tank that leaks from the bottom is usually at the end of its life. Our guide on water heater leaks walks through each spot.

If you also have a pool, a damp equipment area can look similar. Pool leak detection arlington tx homeowners book checks the pool lines separately.

2. The water softener

Arlington's moderately hard water means many garages have a softener. The bypass valve, the brine tank and the drain line are common leak spots.

3. The hose bib and wall pipe

A frost-free hose bib that froze can crack inside the wall. It leaks only when the outside hose is on, and the water shows up inside the garage.

4. The main line and PRV

In some homes the main line and pressure reducing valve sit in the garage. A drip here can be steady.

5. A line under the garage slab

Supply lines to the kitchen or laundry sometimes run under the garage. A leak can make a damp spot or white mineral crust on the concrete.

What can you check safely?

1. Do the meter test. Turn off all water and watch the leak dial for 15 minutes.
2. Put the softener in bypass and see if the leak stops.
3. Close the cold supply valve on top of the water heater if the tank itself is leaking, and turn off its gas or power.
4. Run the outside hose for 10 minutes and check the inside wall for water.
5. Lay a paper towel on any damp spot in the middle of the slab and check it in an hour.

When is it a slab leak?

It may be a slab leak if the meter moves with all water off, the garage floor has a damp spot that never dries, or you see white crust forming on the concrete. Garage slabs are usually thinner than the house slab, but the same tools find the leak. See our slab leak detection in Arlington page for how it works. Slab leak detection runs about $250 to $600, and basic leak detection about $150 to $400.