What Size RV Cover Do You Need for a 42-Foot Camper or Motorhome?
A lot of RV owners start with the same question: "My motorhome is 42 feet long. What size cover do I need?" It sounds straightforward, but the answer usually gets more complicated once you start measuring the actual coach.
The trouble is that motorhomes never seem to take up only the space listed on the brochure. Mirrors stick out farther than expected. Air conditioners add height. Slide-outs change everything and most owners end up wanting more room than they originally planned for.
If you're looking for a starting point, a 46-foot-long cover will usually work. A lot of people move up to 50 feet once they think about day-to-day use. Widths commonly start around 18 feet, while leg heights of 14 feet or more tend to make sense for larger Class A coaches.
If you’re looking for information on finding the right RV cover for oversized campers, motorhomes, and recreational vehicles, this guide will serve you well.
Need help planning a cover around your actual RV size? Explore custom metal RV carports, Design Your Building, or call (866) 681-7846.
Before Looking at Length, Check the Height
Oddly enough, height is often what causes problems first. People tend to know how long their motorhome is. They usually have a rough idea of the width, too.
Ask someone how tall their coach is with the air conditioners installed, and the answer becomes less certain.
A 42-foot diesel pusher can easily stretch beyond twelve feet once rooftop equipment enters the picture. That's why buyers occasionally end up with a structure that looked fine on paper but feels uncomfortably close once the RV is actually underneath it.
A few inches doesn't sound like much until you're staring at an air conditioner that seems a little too close to a roof panel. For that reason alone, many owners start at 14-foot legs. Some jump directly to 16 feet and never think about clearance again.
Length Still Matters—Just Not in the Way Most People Think
You don't necessarily need a huge amount of empty space in front of and behind the coach. You do need enough room that parking doesn't become an event.
A 46-foot cover generally provides enough extra space to make things workable. Plenty of RV owners stop there and are perfectly happy.
The people who choose 50 feet usually aren't doing it because the motorhome won't fit otherwise. They're buying convenience. A little extra room while backing in. Space to walk around the front cap. Somewhere to set a ladder without feeling crowded.
It's one of those upgrades that doesn't seem important during the shopping process and then quietly becomes useful every week afterward.
Planning for a longer coach, ladder space, or future storage? Compare metal camper covers built around your RV dimensions.
Width Depends on How You Actually Use the Coach
Two people can own the exact same motorhome and need completely different cover sizes.
One owner parks the RV and leaves it alone until the next trip. The other washes it regularly, loads gear before every vacation, opens the slide-outs while parked, and spends weekends tinkering with maintenance projects. Those two people use their space differently.
An 18-foot width works well for basic storage. There's usually enough room to walk around the coach and access storage compartments. Once slide-outs enter the picture, however, things change quickly. What looked spacious during the planning stage can start feeling cramped.
That's why 20-foot and 24-foot widths are so common among owners of larger Class A coaches. The RV may not require the additional space, but the owner often benefits from it.
And that's really what sizing comes down to. Not just whether the motorhome fits, but whether the structure remains enjoyable to use five years from now.
Why Owners Rarely Regret Going Bigger
We almost never hear from someone complaining that their RV cover ended up too spacious.
The reason is simple. A 42-foot motorhome is already a large investment. Most owners plan to keep it for years. Some keep them for decades.
When viewed over that kind of timeline, adding a few feet during the initial purchase often ends up feeling inexpensive compared to the convenience it provides over time. That's especially true if the cover eventually becomes more than a parking spot.
Many owners end up using the structure for washing the coach, performing maintenance, loading supplies, or storing equipment alongside the RV.
Cost planning the larger size? Ask about metal building financing options or Rent-To-Own options for camper covers.
Measuring Your Motorhome Before You Call Us
Ordering a custom steel RV cover starts with three measurements: the length of your coach from bumper to bumper, the widest point including mirrors in their folded position, and the tallest point on the roof. Don't forget slides, mirrors, and AC units.
You don't need anything fancier than a tape measure and 20 minutes. Call us with those three numbers and we'll spec out a structure that works. (866) 681-7846.
For general RV measurement context, the RV overall length label can help owners understand why listed RV length and real-world fit may need a closer look.
Frequently Asked Questions
What is the minimum size RV cover for a 42-foot motorhome?
The minimum is 46 feet long, 18 feet wide, and 14-foot legs. That gets a standard Class A coach under cover with basic clearance. If your coach has slide-outs or you want comfortable access on both sides, 20-foot width and 16-foot legs are better numbers to build around.
Do I need a permit for a metal RV carport this size?
Permit requirements vary by county and municipality. Some jurisdictions require a permit for any structure over a certain square footage; others have separate rules for open carports vs. enclosed buildings. We recommend checking with your local building department before ordering. We can provide engineer-certified drawings if your area requires them.
Before ordering, review what to know before ordering a certified building and compare certified metal carport options.
Can I add side panels to an open RV carport later?
Yes. We build our open carports with future paneling in mind. If you start with a roof-and-legs structure and later decide you want one or two enclosed sides, that's a standard upgrade. It's easier to plan for it upfront, but it's not a problem if your needs change.
What is the best roof style for a 42-foot RV cover?
Vertical roofing. It drains water and debris faster than horizontal panels, has a stronger underlying frame, and holds up better in high-wind and heavy-snow regions. On a structure this large, the cost difference is minor. The performance difference is not.
How much does a metal RV cover for a 42-foot motorhome cost?
Pricing varies based on width, height, roof style, side panels, and local delivery.
For payment planning, see metal building financing options and Rent-To-Own options.
Is a 12-foot leg height enough for a 42-foot Class A motorhome?
Almost certainly no. Class A coaches in the 42-foot range routinely measure 12 feet 6 inches to 13 feet 6 inches at the rooftop air conditioner. A 12-foot leg gives you no clearance and likely won't allow the coach to enter the structure at all. Start at 14-foot legs. Go to 16 if you have any rooftop additions.
Can I use a steel RV cover as a workshop or wash bay too?
Yes, and a lot of our customers do exactly that. Adding side panels on two or three sides, a concrete floor, outlets, and LED lighting turns a standard RV cover into a full-service maintenance bay.
The Bottom Line
A 42-foot motorhome needs a cover that's built to match it. That means at least 46 feet of length (50 is smarter), 18 to 20 feet of width depending on your slides, and 14 to 16-foot legs depending on how tall your rig actually measures. Vertical roofing. Side panels if you're in a climate with real winters or if you plan to work on the coach regularly.
We build these structures across the country, fully custom to your dimensions. Design yours at coast-to-coastcarports.com, request a quote, or call Coast to Coast Carports at (866) 681-7846.
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