Waterproof Car Covers
Welcome to one of the hottest topics regarding car, truck and SUV covers. Waterproof Car Covers have been and continue to be a point of contention for cover manufacturers, retailers and the end user.
Our goal in terms of this subject is to provide you with helpful information, along with our recommendations, so that you can make an informed decision about which cover features should be most important to you.
What exactly is a waterproof car cover?
A 100% waterproof car cover is designed and constructed to keep external moisture (i.e. rain, snow, sleet, humidity, condensation, sprinklers, etc.) from passing through all design aspects of the cover (i.e. the material itself, the seams, the hem, the vents, pockets or any other part of the cover). In other words, waterproof car covers act as an impenetrable barrier between external moisture and your vehicle. This means that at no time during a 100°F summer day, or after a hard spring rain storm, or mid-winter with a foot of snow piled on your waterproof cover, should you be able to remove the cover and find evidence of wetness or moisture.
By definition, to be considered 100% waterproof, a water proof car cover fabric must block moisture of any kind from passing through it. Typically, these types of inexpensive protective covers are made from vinyl (PVC) or polyethylene (PE), and are prevalent in low end covers as well as tarpaulins. Since these types of materials compromise breathability, it's not in the best interest of your vehicle to opt for this type of cover.
You may also read about 100% waterproof car covers that are constructed with ultrasonic welded seams. This is a process where heat and pressure are applied to the edges or seams of pattern pieces to fuse them together. Our research over the years has revealed that weatherproof car, truck and SUV covers that have ultrasonically welded seams do help the areas to be more airtight and watertight.
However, testing also reveals welded seams are not nearly as strong as traditional sewn seams, and are likely to come apart with any level of stress the car cover encounters, whether it be from wind or simply fitting the cover over the vehicle. We think that's too much of a trade off, and recommend you consider instead the overall durability of a vehicle cover for the ultimate protection.
We personally know one can spend hours upon hours reading online reviews from concerned consumers relating to waterproof car covers that don't live up to their billing, either because of moisture penetration in the fabric or seam failure. Simply go to Google and enter "car cover reviews" in the search box and you'll see many sites where you can read these reviews.
Your Best Option
Choose water resistance - the only other method for a fabric's ability to block out moisture is to be treated with coatings that prevent moisture penetration. Please note, that while materials can be treated to be highly water-resistant, no amount of coating treatment can completely prevent moisture from penetrating through the cover.
In today's marketplace, you're going to find many types of vehicle cover materials, such as single or multi-layer nonwoven composites, polyesters, nylons, famous brand names or "mysteriously unnamed" fabrics being marketed as 100% waterproof, when in reality the nature of the material at some point will allow moisture to pass through the cover.
But what about those covers with fancy SFS or micro-film layer terminology? Don't some of those say they're waterproof car covers, but can also breathe? Although they say they are, our test studies show they too are not 100% waterproof. Any cover fabric that claims to have the ability to totally block moisture from entering yet breathes out moisture cannot be considered a "waterproof" car cover.
Waterproof vs. Breathability?
In terms of protection, the best material for your vehicle covers are made from fabrics that balance moisture-resistance with breathability. The table below conveys the inverse relationship between these features.
As indicated in the graph, the higher the moisture resistance (Blue), the lower the breathability (Red) and vice versa. A cover's breathablity allows for moisture to evaporate rather than collect on the vehicle. If the cover's material does not breathe, moisture will collect beneath the cover exposing the vehicle's surface and compromising the vehicle's finish. In addition, the lack of breathability in a car cover's material inevitably leads to mold and mildew and an increased chance for rust and corrosion to occur.
For an all-weather vehicle cover, select a material more in line with Fabrics A, B or C. Will any of these covers allow moisture to pass through them? Yes, in some cases they will. But that's okay. Water does not negatively affect your vehicle's surface as long as it has the ability to breathe back out of the cover!
For quick reference to car cover materials available at The Cover Store, click to see which covers offer the best in water-resistance and breathability.