Know your RV’s height. What can happen if you don’t


By Russ and Tiña De Maris

A lot of folks new to the RVing lifestyle are a bit daunted by the size of their rig. They figure all that length can get them into trouble — and it’s true, it takes attention to stay out of trouble. But one of the easier things to forget about with an RV is not so much how l-o-n-g you are, but really, how t-a-l-l you are.

More than one new RVer has returned home from the “maiden voyage” only to report some mishap which has damaged their roof. What’s to be done? Well, 28 grams of prevention is surely worth the old pound of cure.

First, always KNOW your rig height. That information may be provided by your rig manufacturer, but don’t go counting on it. You’ll probably need to do the measuring yourself.

First, from the side of your rig, eyeball to see what the highest point of the rig is. It’s often the air conditioning unit, but some rigs have a higher roof point — often fifth wheel trailers. In any event, figure the high spot, then ascend to the rig top (carefully!) with a tape measure. If an accessory is the high spot, measure from the edge of the roof nearest the high spot, down to the ground. Then measure the distance from the top of the high accessory to the roof level and add the figures together.

Some have suggested using a laser pointer or laser level, parking it at a known height, and shooting the beam over the top of the rig. Then using a yardstick, measure how much lower (or higher) the rig is in comparison to the laser beam. Maybe the easiest system is this: If the highest point on your roof is, say, the A.C. unit, get a long, flat board (1×4 for example), stick it on top of the A.C. unit, let it hang over the side, and measure up to the bottom of the board from ground level. Whatever works.

When the height is known, write it down on a tag, index card, post-it note, whatever have you, and put it in clear sight of the driver’s seat. That will help you when you’re dealing with “marked height” objects like bridges and gas station canopies. Keeping your eye open while driving is essential, of course, unlike the driver of the commercial bus who tried to stuff his 13′ high rig through a 9′ high bridge opening. Driver excuse: “The GPS was set for bus, and it didn’t say anything about this bridge!”

It gets dicier when you’re dealing with unmarked objects. Low-slung tree branches in RV parks and campgrounds cause plenty of trouble. If in doubt, STOP, get out, and eyeball. Or even better, have your navigator hop out and guide you through the problem. Don’t be afraid to get yourself out of trouble (read this: learn how to back your rig up). When traveling through Upstate New York, we had plenty of occasions where we had to back the fifth-wheel away from low bridges — usually kept hidden around a corner with no prior warning.

Now, for that pound of cure: If worse comes to worst, a lot of roof damage can be mended on the road. Unless you’re like that bus driver, what you’re most likely to do (if you’re careful) is to run under a branch and put a tear in your rubber roof membrane. We always keep a roll of EternaBond brand tape in our repair kit. Sold in various widths, 4″ is probably a good one, but we’re a bit cheap and use the 2″ stuff.

Anyhow, should you tear the roof, clean the roof with approved cleaner. This means, NOTHING that contains petroleum distillates or citrus cleaners. These “cleaners” will swell the rubber, cause damage, and likely void your warranty. Make sure the area is clean and dry.

After cleaning, cut a chunk of repair tape around 1/2″ larger than the damage, peel back the liner, and lay out the repair tape on the roof. Now apply pressure to the tape to get it to “tie” into the roof. A steel roller is great for this, but even the pressure of your hand doing a “Dutch rub” will help make the bond secure. Once the tape is stuck down in place, in most cases you shouldn’t have to worry about it again. Nevertheless, a twice-a-year roof check is always a good idea!

EDITOR’S NOTE. Watch a video related to this article on the RV Travel Channel on YouTube.

##RVT769 ##RVDT1250

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1 year ago

A couple of things about this information! You need to take 2 measurements with your RV.

First you have to consider the UNLOADED WEIGHT of the RV. With No Personal Gear in the RV, the RV will sit higher than a Loaded RV. Now, Unloaded means without Water too. Add 100 Gallons of water and you just added over 800 pounds which will cause the RV Springs to Compress and thus lower the RV. Of course this all depends on how much JUNK you take with you on your adventure. Anyway, mark the Unloaded Figure down.

Secondly, Load the BEAST up with all your JUNK, Water included if you haul full tanks. My Water tank is about 25 percent when traveling or about 25 gallons! RE-MEASURE the heighth again and you will be surprised at the difference in Height!

2 years ago, We had the Morryde IS system installed on the 5th Wheel. It is critical on this install for the RV to be level. Final measurement, with the Empty RV was 13 ft. 3 “, to top of each A/C Unit (Front and Back) So, running down the Interstate we’re good. However, being a former Truck Driver, I was trained to read all the signs on the road. (YOU KNOW, those little Yellow warning Signs, that usually indicate something is important to pay attention to!)

And speaking of paying attention: Drivers Need to Pay Attention when rolling down the road, GET OFF THE CELL PHONE and Look out the Window. Let your Passenger do the calling and planning ahead! And Do NOT TRUST those electronic GPS’s. Most GPS’s you buy today are very inaccurate and either will get you lost or put you on a Road you shouldn’t be on with an RV. You need to learn how to read a MAP or ATLAS.

The best Road Atlas (as Chuck describes) is the Truckers Atlas. It shows the routes that Large Trucks can safely travel on. And if they can travel on them, RV’s will usually be OK. However, you still need to pay attention and look out the window and read the signs.

Rand McNally’s Large Scale Atlas is the best one:

This atlas has a section in the front pages with a STATE by STATE index of Low Bridge Clearances. Very handy and will keep you out of trouble!

Knowing the numbers of your RV, no matter what you have, Class A, Class C, Travel Trailer or 5th Wheel. Pay attention to your driving and above all, BE SAFE!