How Trailer Roof Vents Work

A compact camper van on a highway
They're closed for travel right now, but from this angle it sure is easy to see the roof vents on this small RV.
Ian Hamilton/iStockphoto

No matter how clean you keep your home, it always feels good to open the windows and get some fresh air. With no ventilation, things can get a little stale. There's an endless variety of things that can make your home, well, let's just say not the most pleasant-smelling place on the block.

Suppose you own a medium-sized trailer -- it's like a miniature version of your home. You cook, clean, sleep and even bathe in there, so it only stands to reason that, as in your house, you'll need to get some fresh air flowing. The windows are good for that, but unfortunately, the times that you can actually use them are limited. When you're on the road, the highway-speed wind would tear the place apart, and you might risk water damage if it starts to rain.


Depending on what you cooked for dinner the night before or how much dirty laundry you've accumulated, opening a trailer door for the first time in several hours can be a sobering experience. This is especially true if the trailer is in a hot or humid environment. But what can you do? There are times when you simply have to button it up -- you have no other option, right?

The answer is trailer roof vents. Roof venting can provide improved airflow when the trailer is parked or while you're cruising down the highway. If you have the right accessories, they can remain open when you're towing during foul weather, too.

Trailer roof vents do exactly what the name implies -- they ventilate. A trailer roof vent resembles a hinged hatch that swings upward from the surface of the roof. The vent cover opens from the inside of the trailer, typically using a manual crank. However, a few of the more modern roof vents open electrically. Screen material covers the opening to prevent curious animals and bugs from finding their way into your trailer. A small electric fan keeps the air flowing, much like the ventilation fan in your bathroom.

Would trailer roof vents make a worthwhile addition to your trailer? Is it a good idea to tackle this project on your own, or should you leave it up to the professionals? You may want to read the next page before you decide.


Installing Trailer Roof Vents

A trailer roof vent
Installing a trailer roof vent cover, like the one shown here, isn't very difficult -- just make sure it's properly sealed.
Steve Shepard/iStockphoto

Thinking about installing a new roof vent in that old camper in the driveway? Are you ready to cut a 14-inch (35.5-centimeter) square hole (or larger) in the roof? What if you make the hole too large? What if it's not straight? What if you hit a crossmember in trailer's metal framework when you're cutting? What if you cut through existing wires? And, perhaps the worst-case scenario -- what if you can't make the new roof vent water tight?

These questions probably raise some eyebrows, and for good reason -- unless you're a pro at do-it-yourself jobs, installing a brand-new vent is best left to professionals. A licensed RV and trailer repair facility should be able to install a roof vent with little or no problem.


If you're replacing an existing vent, though, the job will be significantly easier, and you may be able to tackle it yourself. Just remember to take very accurate measurements and pay close attention to the way the original vent was installed. If you carefully follow the manufacturer's directions for installing the new roof vent, you shouldn't encounter any unforeseen problems. Properly sealing the roof vent with caulk so that it is water tight is often the biggest stumbling block to a successful installation, so take extra care when completing this step. Spending just a little extra time to make sure that the roof vent is properly sealed will save you time, money and repair bills to fix water damage in the future.

Installing vent covers over roof vents is also comparatively easy. Roof vent covers are the reason that the vents can stay open even during inclement weather. They surround the vent, providing coverage on the leading edge, the sides and the top. The cover is vented on the back to allow the flow of air. Most of the vent cover kits on the market require that you drill a few holes to anchor the cover in place. This is much less involved than cutting a hole in the top of your trailer to install a vent. But because you're drilling into the surface of your trailer, you'll want to carefully follow the manufacturer's instructions for properly sealing these areas.

To read more about towing, roof vents and other related topics, follow the links on the next page.


Lots More Information

Related HowStuffWorks Articles

More Great Links


  • "Roof Vents." (Sept. 30, 2008)
  • KMT Trailer Parts. "Trailer Body Components." (Sept. 30, 2008)
  • Pit Pal Products. "Ventilation." (Sept. 30, 2008)
  • RV Partscenter. "Vents & Roof Supplies." (Sept. 30, 2008)