garage door water diverter

Garage Floor Water Diverters: How To Keep Water Out Of Your Garage

Are you tired of water getting in your garage after heavy rain? Water that backs up on your driveway and seeps under the garage door?

Yeah, me too.

That is why I started looking at solutions to keep my garage floor dry until I could relevel and replace my old blacktop driveway. Years of ground settling caused water to puddle just outside my garage and created a problem that will cost a lot of money to fix permanently.

My goal next Summer is to replace the driveway with concrete and possibly add a channel drain to pull water away from the entrance. But until then, I needed a solution to keep water out of my garage.

Regardless of what is causing water to seep into your garage, there is a wide range of temporary and permanent fixes you can make to protect your garage and garage floor.

How do I stop rainwater from coming in under my garage door?

There are several solutions to this problem depending on the cause.

Some solutions require tearing up your driveway and making general improvements to drainage around your garage. But there are cheaper alternatives like improving weather stripping on your garage door or adding a water diverter to prevent runoff water from getting inside.

Prevention and permanent solutions

The best way to deal with water coming in under the garage door is to prevent it from happening in the first place.

Water can cause all sorts of damage. It can seep into cracks in the garage floor, freeze, and cause bigger cracks. It can also damage items stored on the floor or freeze in the Winter making the floor slippery It can lead to mold growth when it gets into cracks and crevices.

But prevention is often easier said than done.

Inspect your drainage system

The first place to look is the general drainage system. For example, are your downspouts draining properly from your home?

In some cases, downspouts that have overflowing underground drains can back up water at your garage door faster than it can flow away from your home. This allows the water to come under the garage door and onto the garage floor.

If your downspouts drain into the yard, make sure that they drain a minimum of 6′ from the house.

Driveway grading

In order to drain water off your driveway, your driveway should have a natural slope to allow water to flow away from your garage.

Driveway grading and leveling is a permanent solution and may not always be feasible in the short term financially or if there is no slope to work with. It can be quite costly.

If there is not adequate slope, then having a professional install a channel drain where the driveway meets your garage floor is also another great option.

As they replace the driveway, they can install the drainage system at the same time. It will cost extra, but water will then fall into the drain, and the drain pipes underneath can allow the extra water to flow away.

Replace the garage door weatherstripping

If you aren’t getting a lot of water coming in, then inspecting and replacing the weather stripping on your garage door may be all you need.

Replacing your door’s weatherstripping with high-quality weather stripping can seal off where the door meets the floor and prevent water from getting on your garage floor during rain.

You can purchase replacement weatherstripping for garage doors at your local home improvement store, or on Amazon.

Temporary solution for water mitigation

If water is getting in under the door, and you need time to complete one of the permanent solutions like improving drainage, or installing a drain, then adding a garage floor water diverter is a fast, cheap solution.

These devices are made of heavy-duty rubber and act as a barrier to keep water out.

Garage door threshold seals

More commonly known as a garage door threshold seal, these heavy-duty threshold seals, help keep water out but also help prevent rodents, leaves, snow, and debris from getting into your garage. As the garage door closes, the threshold seal is designed to meet the garage doors weather stripping to provide a nice, clean, seal. It also comes with a high visibility yellow stripe at its peak, for visual safety so you don’t trip and fall.

They come in kits of various sizes from 8’5″ up to 20’8″.

The best garage floor water diverter on the market in my opinion is the Weather Defender garage threshold seal.

While cheaper ones exist, the Weather Defender easily installs on the garage floor using adhesive and stays in place when driven over.

Weather Defender Original Ultimate Garage Door Threshold Floor Seal 10'6"
  • Easy to fit, with instant results. Prevents the ingress of water, leaves, dust, debris
  • Suitable for residential and commercial applications, and suitable for all door type and vehicle types
  • Made from ECO friendly PVC. Integrated bright yellow safety strip
  • Anti slip ridges for increased safety
  • Supplied with black adhesive for convenience

The Weather Defender was designed with anti-slip ridges to prevent falls and can be installed in residential, commercial, and industrial settings.

Installation is simple

You install the mats by laying them across the garage floor and taking a measurement. Make sure you buy a size wider than the opening so you can extend the mat past the corners so water does not sneak in around the mat.

If you need to cut the mat, you can use heavy snips to remove any extra length.

Next, apply the adhesive along the bottom of the mat and press to secure the mat to the floor. I added some heavy boxes to help hold down the mats until the adhesive dried. Do not drive your vehicle over it for several hours.

Be sure to read the directions just in case the one you buy is different. This is a simple DIY project that you can do in under an hour.


If you buy the Weather Defender, use your own adhesive. The downside of the product is that they don’t give you enough adhesive to ensure the rubber PVC threshold stays in place. You could reach out to the manufacturer and order more but for my installation, I used Gorilla Heavy Duty Construction Adhesive.

Here is a short video that shows the whole process: