The short answer
Start with the Door Seal
The gap under your garage door is the most common entry point for rain. Over time, the rubber or vinyl strip at the bottom can crack, compress, or pull away. Test it by closing the door and looking for daylight or feeling for drafts. If you see gaps, replace the weatherstripping with a new strip that matches the door width.
Also check the sides and top of the door. The seals there keep wind-driven rain from sneaking in. You can buy adhesive-backed foam tape or a rigid vinyl strip that screws into the frame. Make sure the door still opens and closes smoothly after you attach any new seal.
- Check for daylight under the closed door
- Replace cracked or flattened bottom seals
- Add side and top seals if missing
- Test the door operation after sealing
- Use a threshold seal if water pools at the sill
Seal the Floor-To-Wall Joint
Rainwater can seep through the joint where the concrete floor meets the wall. This gap often appears as a thin crack or a wider separation. Clean out any loose debris, then fill the gap with a polyurethane or silicone caulk designed for concrete. Smooth it with a wet finger for a neat finish.
For larger gaps, use a backer rod, a foam rope that fills the space, before applying caulk. This keeps the seal flexible and prevents it from sinking. Check the joint after heavy rain to see if any water still appears. Reapply caulk if needed.
- Clean the gap thoroughly before sealing
- Use backer rod for gaps wider than 1/4 inch
- Choose a caulk labeled for concrete and outdoor use
- Smooth the bead for a full seal
- Recheck after a storm to confirm it holds
Patch Cracks in Walls and Foundation
Concrete walls and the foundation can develop hairline cracks over time. These let water in during heavy rain. Use a concrete patching compound for small cracks, or a hydraulic cement for wider ones that may be active. Apply with a trowel and let it cure as directed.
For gaps around pipes or vents that pass through the wall, use a waterproof sealant or expanding foam. These are common spots for leaks. If you notice water stains or dampness on the inside wall, the leak may be from the outside. In that case, consider improving drainage outside, such as extending downspouts away from the garage.
Check the Garage Door Threshold
The threshold is the sloped piece at the bottom of the door opening. If water flows over it, a threshold seal can help. These are rubber or vinyl strips that attach to the floor and press against the door when closed. They are easy to install with screws or adhesive.
Before adding a threshold seal, make sure the floor slopes away from the door slightly. If water pools on the floor inside, the slope may be wrong. In that case, you might need a more involved fix, like a floor drain or a raised threshold. That kind of work often requires a professional.
When to Call the Pros
If water keeps coming in after you seal the obvious gaps, there may be a deeper issue. Groundwater can push through the foundation, or the garage floor may be lower than the surrounding grade. A water damage inspection can find the source and suggest the right fix.
Local water damage pros can also handle structural drying if the garage has already gotten wet. They use dehumidifiers and air movers to dry out walls and floors, which helps prevent mold. If you see standing water, act quickly to remove it and start drying. See a doctor if you feel unwell from any mold exposure.
If the problem is a leak from a pipe or a roof, a plumber or roofer may be the right call. For sealing work, you can often handle it yourself, but for persistent water, professional help is worth considering.
- Persistent leaks despite sealing
- Water stains on walls or ceiling
- Standing water after rain
- Mold growth or musty smell
- Foundation cracks that widen
Water damage does not wait
Phones are answered 24/7 for Layton and nearby communities.
Call Now (801) 383-0232Frequently asked questions
What is the right sealant for a garage floor crack?
For small cracks, use a polyurethane or silicone caulk labeled for concrete. For wider gaps, a backer rod plus caulk works well. Avoid latex caulk because it dries hard and cracks. Always clean the crack first and let it dry completely before applying the sealant.
Can I seal my garage door from the inside only?
Yes, you can apply weatherstripping on the inside of the door, but it may not be as effective as sealing the outside. Rain driven by wind can still push under the door. For sensible results, seal both the bottom and the sides, and consider a threshold seal on the floor.
How often should I replace garage door seals?
Check the seals at least once a year, especially before the rainy season. Replace them if they are cracked, brittle, or no longer press against the door. With normal wear, a good seal can last several years, but sun and temperature changes can shorten that.