First of all, yes, by design, tonneau covers are waterproof. This is the way these pickup truck trailers work and why customers buy them for convertible car toppers. However, not all tonneau covers are going to stop all the rain.
I am here to help you figure out which ones of the tonneau covers on the market are really waterproof, and those that are more susceptible to leaking. Let me help you decide on the right tonneau cover for your truck or car today.
Related: Tonneau Cover vs. Canopy: Which One is Better?
Is My Tonneau Cover Waterproof at All?
“The short answer to this question is, when properly installed, a tonneau cover will keep the vast majority of water from entering your truck’s bed.
To describe a tonneau cover as 100% watertight or waterproof would be inaccurate, but the most you’ll usually get are a few drops intruding during a rainstorm,” according to Real Truck. For anyone who owns a vehicle that has an exterior cab or trailer, having a protective tonneau offers much-needed coverage.
Which Tonneau Covers are Best Suited for Rain?
There are several styles of tonneau covers made for protecting vehicles from rainy conditions. However, certain ones really are constructed more suitably for heavy rain on a regular basis.
“[The] most weather-resistant tonneau covers, in order: hinged tonneau covers; retractable tonneau; and hard-folding tonneau,” says Part Catalog authors. Here is a breakdown of these three well-made tonneau covers for wet conditions.
About a Hinged Tonneau Cover
A hinged tonneau cover is a covering that has been permanently installed into the truck or vehicle bed. A hinge is attached to the bed using screws or bolts so that the tonneau cover cannot be fully removed at any time.
This permanent placement helps to create a more weather-proof and water-tight seal in terms of the tonneau cover. You can find hinged and folding tonneau covers, but generally, this style of covering is a single panel that can be lifted up.
About a Retractable Tonneau Cover
A retractable tonneau cover is similar to the hinged tonneau cover. I really prefer this style myself as you have the hinged system, once again, but the cover is typically made from a soft body canvas material. As a result, it is much easier to roll up the retractable tonneau cover as if this were an awning for your vehicle.
The retractable tonneau cover is less expensive compared to a hard folding or tri-fold tonneau cover. This is another reason why it is a more popular choice.
Also, the soft body material of the retractable tonneau cover is lighter in weight. If you are someone who worries about spending a lot on fuel, the heavier the tonneau cover, the more costly the mileage on your vehicle. This is when buying a soft canvas tonneau that is retractable would be the right option.
However, retractable tonneau covers made from canvas are more likely to rip or be stabbed with a knife in the instance of vandalism or theft.
For auto owners who live in a dangerous neighborhood or have high priced items, such as tools, stowed under the tonneau cover–a hard folding style is much more suitable. Again, the biggest issue with the retractable tonneau made using canvas is also the waterproofing aspect.
You will have the best luck with waterproofing your canvas tonneau cover, if it is at least hinged and potentially retractable. This adds to the waterproofing aspects and helps reduce moisture inside the cab or bed.
Related: The Birth and Wild Growth of DiamondBack Tonneau Covers
About a Hard-Folding Tonneau Cover
The third type of tonneau cover I have found to be most beneficial against water damage is the hard-folding tonneau that I have briefly touched on.
The hard-folding tonneau is suited for weather conditions and can even hold heavy weights on top when installed. This style of tonneau can be either hinged or foldable, but it will always be made from hard body material.
You can fold the tonneau into panels and secure it safely to the bed of the vehicle, if it is attached using a hinge. Truck drivers and owners who are hauling equipment and accessories prefer to use a hard-folding tonneau cover.
This is because the cover is well suited to holding items on top of the tonneau cover. You cannot do that with a soft body canvas tonneau cover at all without destroying the integrity and shape of the cover.
How does the hard-folding tonneau cover handle wet weather and heavy rain? Here you are working with hard panels that are made from steel framework and coated with a waterproofing material.
This is applied with a spray to secure the metal and protect it from rusting. When using this type of tonneau cover, the concern of rusting is always right around the corner. That is why waterproofing sealants are applied to protect the cover.
For reference, I had a professional apply the waterproofing material to the inside of my truck bed as well for extra protection against rusting.
That’s because I use my pickup truck to haul wood and other winter gear in the backwoods of Alaska. The only way to save my old truck is waterproofing everything I can. It really does do the trick!
If you are like me and live in Alaska, consider the Renegade heavy duty style of tonneau covers. According to the manufacturer, “The Renegade heavy duty tonneau cover is built to resist harsh weather like rain, dirt, and snow.”
If you buy the tonneau cover in mind with the end weather you will use it for, then you stand the best chance of getting the most waterproofed tonneau cover for your bucks.
How Are Tonneau Covers Waterproof?
Technically, the use of the tonneau cover is a waterproofing feature that is used for covering up a bed in a vehicle. This is used for an exterior cab or trailer that would otherwise be exposed to water.
Therefore, by adding a tonneau cover to a vehicle, this adds a waterproofing element. However, the waterproofing goes even further.
Most of the tonneau covers are made using waterproof material, such as vinyl or rubber. This material may also be treated using a waterproofing substance like a spray or varnish.
By adding the pretreated tonneau cover to a vehicle, you get even more protection against rain, snow, or other forms of wetness.
Are Tri-Fold Tonneau Covers More Waterproof Than Canvas Tonneau Covers?
A tri-fold tonneau cover is made from steel or another super hard material. These are the most expensive style of tonneau covers on the market. Therefore, you hope to get the most bang for your buck.
However, even the most expensive tri-fold tonneau covers have seams and can leak. Yet, when it comes to comparing tri-fold hard body tonneau covers to canvas materials, there is a reason the former ones are the most costly. A hard body tri-fold tonneau cover has at least three fully encased segments that will never leak water through the material.
That cannot be said for canvas. When you are working with a material that is sewn with threads, there are fine gaps that will naturally allow for leaks. Woven material can be treated with waterproofing sealant, as well, which will increase leak resistance.
Yet at the end of the day, if you are most concerned about waterproofing your vehicle, the tri-fold tonneau covers are more waterproof by design.
Do Tonneau Covers Rust With Age?
I have had a tonneau cover for my old pickup truck for about 10 years now. So far, there has been no signs of rust. There is the issue with this being a rigid hardbody tonneau cover and metal fixtures.
While I am concerned about rusting in the metal works, this is not a problem so far. Now that being said, I wonder about those tonneau covers that are not as well built. The lack of solid construction would most likely lead to rusting for tonneau covers that contain metal.
Of course, those tonneau covers made from soft canvas materials are not going to rust because they are metal-free.
If you are someone who lives in a humid or wet environment, or at the beach, where your tonneau cover is hit with rain or water every day, I would be concerned–only if it contains metal works.
In this case, having a tonneau cover that is soft would be preferred over a hard-style tri-fold tonneau cover.
Also, as noted earlier, if you have a hinged hard-folding tonneau cover that is steel on the inside, choose a waterproofing sealant. The spray style applied by the professionals is the only way to go here.
When you do this, you truly protect your tonneau cover from rain and moisture. You also ensure a long life of protection from the elements using your new tonneau cover.