Are Tonneau Covers Waterproof?

Tonneau covers are designed to protect your truck bed from the elements, but they're not entirely waterproof. According to most online users found on forums or Reddit, you can consider tonneau covers to be around 98% waterproof. Most are water-resistant, meaning they can handle light rain and splashes, but in heavy downpours or car washes, some water might seep through, hence the 98%.
Nonetheless, the water that slips through is minimal, to the point it can be considered mostly condensation, and it must be pouring for hours. It must be noted, that not all tonneau covers are waterproof, what has just been explained applies only to covers that are advertised as waterproof.
Are All Tonneau Covers Waterproof?
If a tonneau cover is waterproof or not, depends on the materials it is made of, as well as the design. A waterproof tonneau cover is either made of plastic, PVC, a fully waterproof canvas, aluminum, or a hard tri-fold cover. A canvas or fabric tonneau cover is unlikely to be waterproof, so do check beforehand.
Assuming we are talking of waterproof tonneau covers only, their level of protection completely depends on their style or design: hard covers, like hinged or retractable ones, generally offer better water resistance compared to soft roll-up or folding covers. Proper installation and maintenance, such as ensuring the seals are intact the installation is even, will ensure it’s as waterproof and watertight as possible, However, if keeping your cargo completely dry is crucial, it's wise to use additional waterproof storage solutions inside the truck bed.
Despite advertised as fully waterproof, tonneau covers tend not to be 100% waterproof, or not to be able to fully guarantee a watertight performance all the time and after years and constant use go by. While they offer significant water resistance, especially high-quality hard covers, some water can still go in during heavy rain or car washes.
Proper installation is key, for example, if the sides of the cover aren’t even, water can get in through narrow slits. Maintenance is also needed. For example, a tri fold cover will require you to make sure the hinges are protected, or if there are bolts, make sure they don’t loosen over time, letting water drip through them.
Types Of Tonneau Covers And Their Water Resistance
1. Hinged Tonneau Covers: These one-piece covers, normally made out of hard plastic or even aluminum (see DiamondBack covers), provide excellent if not the best water resistance due to their seamless design. They overlap the tailgate and bed rails, minimizing water entry points, but again, make sure there are no slits here where the water can flow through!
2. Retractable Tonneau Covers: These are like the Retrax XR< and nowadays the most popular since they are sometimes automatic, and some can even be used with a bed rack. They are normally built out with aluminum slats and they retract into a canister. Most of them have special compression seals that will channel the water away.
3. Hard-Folding Tonneau Covers: Made from hard plastic panels, these covers provide good water resistance, and should normally be a solid 98% waterproof. However, the seams between panels can be a “weak” point, they must be checked yearly to make sure they aren’t giving in with the constant use and folding.
4. Soft Roll-Up and Folding Tonneau Covers: These are perhaps the most affordable tonneau cover models, made out of wither vinyl or PVC, which are fully waterproof materials. However, the weak points are the edges, which aren’t fully water-tight like other hard cover models, meaning water could seep through those edges.
Factors Affecting Water Resistance Of Tonneau Covers
· Quality of Seals: You want all seals to be as water-tight and in best condition as possible. Seams, edges, heck even the bolts need to be water-tight. A brand new tonneau cover should in theory have all of this covered, but we all know there can always be minor flaws, hence the 98% waterproofness.
· Installation: The biggest reason for water to seep into a truck bed is due to a faulty installation. Uneven sides, unsealed edges, damaged seams. Make sure to triple-check the installed cover.
· Maintenance & Use: You will open and close the tonneau cover constantly, this leads to parts of the cover potentially loosening or degrading. A tri-fold cover could have the seams get damaged with use. A retractable cover could suddenly see the edges suffer some degradation from the rubbing to other materials or surfaces, bolts can loosen and allow water through them, or worse, you forget to close it! Give the tonneau cover the proper maintenance and you’re good to go!
Enhancing Water Resistance Of Tonneau Covers
Enhancing the water resistance of the tonneau covers is a possibility but not exactly necessary. This is only if what you’re transporting is really going to be valuable enough not to get wet, ever.
· Additional Weather Stripping: Make sure to add extra weather stripping to vulnerable or “weak” areas, such as the tailgate, and edges of the cover.
· Drainage Systems: The cover as well as the bed of the truck have drainage systems, keep your items as far away as possible from them in case water needs to flow out, and as well remove any debris, elements or whatever fell into these drainage systems to avoid clogging and overflowing of water.
· Protective Sprays: Using waterproofing sprays designed for tonneau covers, canvas, PVC, or vinly, can add an extra layer of protection against moisture.
Let’s Wrap It Up
In conclusion, tonneau covers are 98% waterproof. Yes, they will be good 98 out of 100 times, where it can rain as hard as you can imagine and still no water will slip into the bed of your truck. Your chances improve if you actually purchase the best tonneau cover possible. However, there is always that small chance that it happens, and to avoid that, just follow the guidelines mentioned in this article, and you’ll be certain it will be a 100%.