Do RV Covers Cause Mold?

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Updated October 11, 2025

When Susan and I first started RVing, we didn’t think much about RV covers. We figured parking the rig in the driveway and giving it a wash before each trip was enough.

But after one long winter, we noticed some oxidation on the paint and a few brittle seals. That’s when we started learning how a quality RV cover can make a world of difference—if used correctly.

The question we hear most often is: Do RV covers cause mold? The short answer is no, not if you use the right one and install it properly. Let’s talk about how to choose the best RV cover, how to use it correctly, and how to make sure you don’t accidentally trap moisture that can cause mold or mildew.

What Is an RV Cover and Why Use One?

An RV cover is designed to protect your rig from the elements—UV rays, rain, snow, and even wind-blown debris. Think of it as sunscreen and armor for your RV’s exterior.

A good cover prevents fading paint, cracked seals, and water intrusion that can lead to costly repairs. Some RVers believe covers are only needed when winterizing their RVs, but that’s a myth. They’re useful year-round. Sun, rain, and wind are just as damaging as snow.

In fact, UV rays are the biggest long-term threat to your RV’s finish and roof integrity. If you store your RV outdoors and don’t have access to covered or indoor storage, an RV cover is one of the best investments you can make to protect your rig’s value.

Do You Really Need an RV Cover?

If your RV is exposed to the elements for long periods—even just a few months—an RV cover is worth considering. Every time we travel, we see rigs that have been sitting uncovered all season. You can always tell—the decals fade, the seals dry out, and the roof starts to show signs of chalking.

Covers are especially useful if you don’t have access to covered storage, you store your RV outdoors for the winter, or you live in a hot, sunny, or coastal area where UV or salt air can damage finishes. Even if you only use your RV a few times a year, a good cover helps maintain its resale value.

For extra protection, we also use RV tire covers—tires are one of the first things to deteriorate in the sun.

What Are RV Covers Made Of?

Most RV covers are made of either polyester or polypropylene fabric. Both protect against the elements, but they differ in breathability and durability.

Polyester RV covers are more affordable and often treated with a water-resistant coating. They protect against rain and UV rays but aren’t as breathable, so they may trap moisture if your RV isn’t completely dry underneath.

Polypropylene RV covers cost more but are stronger, tear-resistant, and breathable. Breathability is key because it allows moisture to escape, helping prevent mold and mildew. If you live in a humid area, polypropylene is worth the extra cost.

When we upgraded to a polypropylene cover for our Class A motorhome, we immediately noticed less condensation inside after a rainstorm—a big improvement over the cheaper polyester model we tried first.

Do RV Covers Cause Mold?

This is the big question, and here’s the truth: RV covers don’t cause mold—trapped moisture does. If you throw a cover over a damp RV or use a non-breathable tarp, you’re creating a sealed environment where humidity can’t escape. That’s when mold grows.

Here’s how to avoid that: clean and dry your RV completely before covering it, use a breathable RV cover (preferably polypropylene) with built-in air vents, avoid covering your RV right after rain or washing, and allow airflow underneath—don’t cinch the straps so tightly that air can’t circulate.

If you live in a humid region, you might even consider placing moisture absorbers inside the RV while it’s covered. This helps regulate interior humidity and keeps mold at bay.

Why You Should Never Cover an RV With a Tarp

It’s tempting to grab a blue tarp from the hardware store, but don’t do it. Tarps aren’t breathable and will trap condensation against your RV’s surface. Worse yet, when the wind blows, the tarp can rub against the paint, scratching and dulling the finish.

A tarp is fine as a temporary fix for an emergency—say, if you have a roof leak—but it should never be your long-term storage solution.

How to Choose the Right Size RV Cover

Before buying, measure your RV’s length, width, and height carefully. Most RV covers are sold in size ranges—for example, “fits 20-24 ft.” If your rig is 23 feet long, that size should work perfectly.

Avoid covers that are too loose or too tight. A loose cover can flap in the wind, scuffing your paint and causing tears. A tight cover is difficult to install and more prone to ripping at seams or corners.

We learned this lesson the hard way when we bought an oversized cover for our Gulf Stream Class C. After one windy week at the storage lot, the edges of the cover were shredded and the paint had light scuffs. Measure precisely and secure it snugly, but not tightly.

How Much Do RV Covers Cost?

RV cover prices range from just over $100 to more than $1,000 depending on size, materials, and brand. You don’t have to buy the most expensive option, but avoid the cheapest ones—they often lack breathability and tear easily.

We’ve found the best results by choosing a mid-range polypropylene cover with built-in vents and reinforced corners. Before you buy, read reviews from RVers who live in a similar climate. What works great in Arizona might not hold up as well in Florida humidity.

Final Thoughts: The Right RV Cover Prevents Mold, It Doesn’t Cause It

A quality, breathable RV cover can protect your investment and extend the life of your RV—as long as you use it correctly. The key is dry before you cover, choose breathable materials, and allow air circulation.

Mold isn’t caused by the cover itself but by moisture that can’t escape. Susan and I always say, “If you’re willing to spend tens of thousands on your RV, it’s worth spending a couple hundred more to protect it.” Covering your rig the right way keeps it looking great and ready for more adventures on the open road.

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Related Reading:

– The Pros And Cons Of RV Or Camper Covers

– Indoor Versus Outdoor RV Storage Facilities

– 10 Best RV Windshield Covers Reviewed

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