Waterproofing Your Garage in the Pacific Northwest

It’s no secret that the Pacific Northwest offers a wealth of beautiful weather and scenery. Unfortunately, it comes at a dampening cost. Nearly seven months of frequent rainfall to be exact. Needless to say, the rainy season can cause repeated frustration for homeowners living in the Portland-Vancouver area, as rainwater seeps, creeps, and runs where it’s not welcome — including right under your garage door.

The presence of water in your garage can cause a number of issues, such as cracked floors, rotting garage doors, damage to items stored in your garage, and moisture build up. These problems don’t just stop there. Garage moisture can actually have a very negative effect on the rest of your home, contributing to mold and mildew growth that pose serious health risks to you and your family.

Ways to Prevent Water from Entering Your Garage

Water infiltrating your garage door can occur for a number of reasons, some easier to fix than others. Depending on the scope of your garage problem and its location in relationship to your driveway, a few simple steps might help. In some cases, however, costly drainage measures are necessary to fix the problem.

Garage Door Seals

You’ve likely noticed the rubber seal stretching across the bottom of your garage door. Also known as an “astragal,” these seals should press snugly against the floor when the garage door is closed. It’s not uncommon, however, for the elements to cause these seals to deteriorate, tear, and even shrink over time, allowing water and pesky insects to travel freely under your garage door. Inspect the seal on your door. If you notice any tears or raised edges, you may simply need to replace your garage door seal.

Raised Seals

For minor water problems, you may also consider installing a raised rubber seal on the floor of your garage. Similar to a mini speed bump, these seals act as a barrier and help prevent water from seeping in. Raised seals come in a variety of styles and sizes, and for all you DIYers, require little more than glue for an easy installation.


If you find water pouring off your roof and down your garage during heavy rainfall, you may need to replace the gutters along the edges of the roof. Make sure to attach downspout extensions that carry rainwater out and away from your garage door. Along with keeping rainwater out of the garage, diverting the water away will also help protect your home’s foundation. Of course, grab a ladder first and inspect. The fix may be as simple as routinely clearing out fallen debris from surrounding trees.

Trench Drain

If your driveway slopes downward toward your garage rather than away, you may be looking at a more costly solution. Whether heavy rainfall or a light trickle, the only way to keep the rainwater completely out is to channel it away before it can run under the garage door. The best way to accomplish this is to install a trench drain along the front of the garage. Although extremely effective, this solution can be rather costly and require professional assistance.

Battling Condensation In Your Garage

Along with rainwater infiltrating your garage door, homeowners in the Pacific Northwest must also beware of condensation buildup in their garage. Condensation occurs when excessive water vapor comes into contact with a cold surface. If left unattended, condensation in the garage can create an uncomfortable and potentially hazardous living environment, impacting temperatures throughout the home and even contributing to mold growth. Here are a few ways to mitigate condensation in your garage.

Heat Your Garage

The temperature of your floors, wall, and other surfaces must be lower than the temperature at which water condenses (aka the dew point). Regulating the temperature in your garage will help prevent condensation and moisture buildup. Propane heaters, however, actually create water vapor and should be avoided. Your best bet is to use an electric heater.

Use Vapor Barriers

If installed properly, vapor barriers will help keep garage condensation at bay. Using an insulation product with a built-in vapor barrier is always preferred. Otherwise, you can simply install plastic vapor barrier sheets directly over your existing insulation. Be sure to avoid ceiling vapor barriers as they tend to keep water trapped inside the garage.

Dry Your Vehicle

After driving in the rain or snow, try to dry your car as best as possible before parking it in your garage. It should only take a few minutes but will significantly reduce the risk of excess condensation forming in your garage.

The garage door specialists at Larry Myers have been installing and repairing garage doors in the Portland-Vancouver area since 1973. We have the solutions to all of your garage door needs. If you are uncomfortable performing any of these projects or if you want to learn more about how to stop water from leaking under your garage doors, give us a call at (503) 761-5674.