How to Keep Water Out of the Garage: A Handy DIY Guide

By: Diana Rodriguez-Zaba
Updated on: February 13, 2024

You expect a little water in the garage after a heavy rain. It drips off the parked car, but it quickly dries up. You don’t expect to see water seeping up through the concrete garage floor or forming damp spots on walls.

How do you figure out what causes wet garage floors and walls? How do you fix something you can’t always see? 

Our water restoration services cover everything from soaked attics to flooded garages, so we’re very familiar with this homeowner’s headache. We offer you our quick guide to identifying and solving common water problems in the garage.

Wet Walls in the Garage: Finding and Fixing the Problem

You can’t see through them, so it takes a little handyman detective work. Water leaking into the garage under a wall or from behind sheetrock is usually caused by one of these problems.

1. Old Joint Seams

Old joint seams on exterior walls are prone to leaking during stormy weather. Inspect wall seams especially around doors and windows. Save yourself from dealing with soaked sheetrock by sealing garage wall seams with caulk or waterproof foam.

2. Aging Sill Plates

Water in the garage might be a sign of leaking around old sill plates. Check horizontal sills at the bottom of framed walls where they meet the floor. Bad sills should be replaced, but caulk or foam often stops leaks.

3. Faulty Plumbing

A water heater or washing machine can develop water line problems behind a wall. If you find puddles on the garage floor along the same wall as an appliance, you may want to call in a plumber to find and fix the leak.

4. Roofing Problems

Loose flashing and bad shingles let rain into exterior walls where it travels along framing studs. As water moves to the bottom of the wall, it seeps out onto the garage floor. Identify and fix roof problems, and check gutters too.

A Wet Garage Floor: Causes and Solutions

Water seeping up through a concrete garage floor is often the result of a seasonal rise in the water table. It’s hard to control deep soil moisture around the house, but you can address water on the garage floor by fixing these flaws.

1. Floor Cracks

Even when they’re small, they provide a direct route for ground moisture into the garage. Repair floor cracks by cleaning them thoroughly and filling in with a water-resistant concrete patching compound.

2. Surface Pitting

Older concrete floors eventually become pitted with tiny holes that become wells for moisture. Treat the entire floor by sealing it with a silicate-based product. Avoid regular floor paints that don’t lay down a moisture barrier.

3. Warm-Weather Condensation

Warm air on cool concrete creates a vapor that settles and turns into water on the garage floor. The solution to this spring and summer problem is simple. Run a dehumidifier in the garage, but be sure to regularly check its reservoir.

Water Under Garage Doors: Keeping Out Rain and Snow

Sometimes, knowing how to stop water from coming into the garage starts at the door. Keeping it closed during bad weather isn’t enough when you have one of these problems.

1. Worn-Out Weather Strips

The rubber strip along the bottom of a garage door eventually wears out and lets in rain, melted snow, wind-driven debris and even bugs. When you replace it, give it backup against stormy weather with raised rubber floor seals.

2. Driveway Grade

If the ground next to your driveway is slightly higher than the concrete, heavy rains can fill up the driveway and seep under the garage door. Make lowering the grade next to your driveway a priority landscaping project.

3. Driveway Pitch

Elevation counts again if the garage is built partially below your property’s grade line. Compensate for the driveway’s slope down into the garage by installing a channel drain to redirect water away from the garage door.

Dealing with Water in the Garage in Chicago, IL? We Can Help

Over the years, your garage becomes the go-to spot for home storage. It doesn’t take long for wet walls and floors to give the garage a musty smell and feel. All that damp eventually seeps into stored belongings and results in mold and mildew. Use our guide to zero in on wet garage problems and solve them too.

If your garage suddenly fills up with several inches of water, call us right away. Our certified water cleanup professionals are standing by 24/7 with the best restoration services in Chicago and the suburbs. We even handle mold remediation and small plumbing repairs. You can always depend on us here at ServiceMaster Restoration by Zaba.

Call us now for emergency help: 773-647-1985

How do I get mold off wet garage floors?

Start by clearing out the garage and sweeping the floors. Scrub moldy concrete floors with a mixture of water and white vinegar or a diluted bleach solution. Always work with the garage doors open to fresh air.

How much does garage door weather stripping cost?

Garage door weather stripping is sold in lengths. Expect to pay between $10 and $15 for a 16-foot rubber strip that seals a two-car garage against rain and humidity. You can also buy PVC or vinyl garage door weather stripping.

Can I waterproof masonry garage walls?

Yes. Prep the walls by scrubbing them clean. Fill in any holes or cracks with masonry joint filler or crack sealant. Wait several days, and then paint garage walls with two coats of a latex-based masonry waterproofer.