You might be considering a career in truck driving, or maybe you’re just curious about what a semi-truck sleeper looks like.
Exactly What Is A Truck Sleeper or Sleeper Berth?
A semi-truck sleeper is legally referred to as a sleeper berth. This space is more like a small room with a dedicated bed area for sleeping. Most truck sleepers also provide storage space for clothing and supplies. Since many of us live in our trucks for weeks, even months at a time, the average truck sleeper is far beyond the legal requirements.
Semi-truck sleepers generally fall into one of three categories. Each serves its purpose in the trucking industry.
- Flat-top sleepers – The sleeper portion is only as high as the truck’s cab.
- Mid-roof sleepers – The sleeper is higher than the cab, enough so that the driver has ample room to stand up inside.
- Condo sleepers – Often equipped with an upper bunk bed, Condo sleepers can have well over 8 feet of interior headroom.
I’ve spent my share of time in each of these sleeper configurations. They all serve a purpose.
What Is The Smallest Legal Size Of A Truck Sleeper?
A DOT-approved sleeper berth must meet the following requirements;
- Minimum of 75 inches long
- At least 24 inches wide
- At least 24 inches high
- Have an easy entry and exit from the cab
- Be separate from any cargo compartment
- Have a qualifying mattress, bedding, and heat supply
This is just a brief overview. Everything from safety restraints to the radius of the sleeper corners is defined in by the Federal Motor Carrier Safety Administration. Here’s a brief rundown from Cornell Law School’s website if you want to learn more.
Why Choose A Flat-Top Sleeper?

Flat-top sleepers offer three competitive advantages.
- They are more aerodynamic if you’re hauling lower-height loads on flatbed trailers.
- All other things being equal, the flat-top is lighter than the other sleeper options.
- In most cases, flat-top sleepers are the least expensive.
The blue and white truck pictured above is a 2010 Peterbilt with a 48″ flat-top sleeper. The company I worked for purchased the truck for exactly the reasons I listed above. The bed was only 36″ wide, but it was comfortable.
Because of the narrower bed, I did have enough room to stand up to get dressed, even though I couldn’t fully stand upright.
Equipped with a C-13 Catipiller engine and 13-speed transmission, the truck was shorter and lighter than the other trucks in their fleet. I used this truck for almost two years.
The red pieces on the trailer are 24-foot decks for truck scales. There are 3 in the picture. With the light truck and an aluminum trailer, I could load 6 of these decks, something the trucks couldn’t do.
I’ll be the first to admit that I missed the extra room in the larger sleepers. However, since I never took passengers, removing the passenger seat helped provide space for 2 to 3 weeks of provisions.
Why Don’t More Trucks Come With Flat-top sleepers?

This flat-top sleeper truck had one other disadvantage. Nobody else wanted to drive it. Most of my coworkers weren’t willing to give up a bigger sleeper and a longer, smoother-riding truck to take the heavier loads.
Flat-top sleepers can be larger than the 48″ model I used to drive. Peterbilt’s 63″ flat-top is a popular option for flatbed truckers who want a little more room. The extra space leaves more room for creature comforts like a refrigerator, Microwave, and a full twin bed.
Another drawback of most flat-top sleepers is the lack of overhead bins in the cab area. Look at the actual cab roof in both the flat-top and mid-roof trucks. You’ll notice the mid-roof cab is nearly a foot higher than the windshield and door glass.
This extra room makes it a little easier for the driver to navigate from the driver’s seat to the sleeping area. It also provides a bit more room for extra storage bins above the glass. These handy bins are missing in the flat-top sleepers.
The bottom line is that smaller sleepers provide adequate sleeping space. What they don’t offer is a more generous living space.
Are Mid-Roof Sleepers Big Enough?

Mid-roof sleepers give the best of both worlds in some ways. Built with a lower profile, they can still be more aerodynamic for flatbed loads. But they can also have a roof fairing that makes pulling a 13’6″ high van trailer as aerodynamic as a condo sleeper.
The truck I drive as of this writing is equipped with a 72″ mid-roof sleeper. An upper bunk is an option in most mid-roof offerings, but this truck doesn’t have one. the ceiling height is about 77″, giving me plenty of room to stand.
As you will see in the pictures of my truck, the company opted to install extra cabinetry in place of the upper bunk. Since I spend more time than most on the road, those cabinets are used well.
Mid-roof sleepers are an excellent option for a solo driver but for a team driver operation. And with a larger length like this 72-inch sleeper, I have plenty of room to sleep, stand and even exercise. This sleeper also has a refrigerator, microwave oven, wardrobe, and enclosed cabinets for storage.
Another advantage of the mid-roof is a larger market to sell the truck when it’s time to replace it.
Nearly anyone looking for a used semi-truck to pull a van or refrigerated trailer wants the aerodynamics offered by the mid-roof or condo sleeper.
On the other hand, the flat-top sleeper is mostly limited to those pulling flatbed trailers.
Authors Note: I must add one advantage I liked while driving a condo sleeper. As a fitness junkie, I enjoyed lifting weights over my head and doing other full-stretch exercises. It’s really the only thing I miss now that I’m in a mid-roof sleeper.
Condo Sleepers Are Great For Team Drivers

One of the benefits of the tall ceiling height in a condo sleeper is the headroom it allows the occupants when they’re in the bunk. Whether it’s the upper or lower bunk, there’s room to sit on your bed and read, use your laptop, or do whatever else you want.
You also have the advantage of the higher side windows for venting air through the sleeper.
Honestly, the extra interior height is mainly wasted on a single driver. At least, that was the case for me. Leaving the upper bunk down just created a place for junk to collect. It also closed in the otherwise open area.
On the other hand, I’ve seen other people use the upper bunk for office space or just a second place to relax.
Besides the bunk height, I don’t see any advantage of the permanent high roof line. It’s always there, and your height is permanently set at about 13’4″.
How Big Is The Bed In A Sleeper Truck?
Although the smallest sleeper bed allowed by law is small enough to fit in a 24″ wide sleeper, most semi-truck sleepers are equipped with a twin mattress, 38″ by 75″. Mine has a twin XL mattress, adding an extra 5 inches to the length.
Larger sleepers are often equipped with bunk beds. The top bunk will fold up against the back wall when not used. Rather than have that top bunk, the company I work for decided to utilize some of that extra space for more storage. Since I stay out for longer periods than most, it’s quite handy.
Authors note: I’ve left custom-built sleepers out of this article entirely. Needless to say, you can have anything you want in a custom-built truck sleeper. The only limitations are the added weight, the length of the truck, and of course, the size of your budget.
Do Semi-Trucks Have Refrigerators?
As you can see in the pictures, my truck came from Peterbilt with a built-in refrigerator. It even has a small freezer space.
I drove sleeper trucks for years without the benefit of a built-in refrigerator, but I always had one in the truck. There are several options available for 12-volt coolers and refrigerators. The trade-off is since it’s not built in, it will take up space elsewhere.
This 12-volt cooler by Colemen is a staple of the trucking industry. It’s not a refrigerator and has no thermostat. This cooler will lower the temperature by about 40 degrees in whatever climate it’s in.
Should you shut your truck off and let the interior cool to 60 degrees, you can count on a few things starting to freeze by morning.
Likewise, when your truck is parked in the hot sun, and the interior gets warm, the inside will only run about 40 degrees below that temperature.
I had excellent service out of mine. I just kept an eye on it and unplugged it when necessary.
There are also a number of 12-volt refrigerators available, but they are a bit more expensive. They’re also heavier since they have a compressor.
How Do You Cook In A Semi-truck?
Although some custom-built sleepers have cooking facilities, most sleeper trucks don’t have that capability. That doesn’t mean a driver can’t prepare a meal in his or her truck.
This truck provides adequate space for a microwave oven. Although I chose the conventional microwave, several of my coworkers chose a microwave/air fryer combination oven. I have to admit; it’s on my wish list.
Because of the industry I serve, many of my meals are provided. But I do still enjoy preparing my own meals from time to time. When needed, I use a single-burner butane stove. I place it on the small countertop built into my storage cupboards.
I also like taking the portable stove outside should I decide to cook fish or some other meal I don’t want smelling up my sleeper.
How Do Truckers Stay Warm Or Cool When They Sleep?
Much like the sticks and bricks home, there are various ways to keep the interior of a truck at the ideal temperature for sleeping. Diesel fuel is expensive, and many states have anti-idling laws on the books. Leaving a truck engine idling all night long is much less common than it was 20 years ago.
In colder weather, most sleeper trucks have a diesel-powered furnace. These are commonly called bunk heaters. Priced at around $1,300, these little heaters will pay for themselves in less than one typical winter.
You can buy a Chinese knock-off version of these bunk heaters for under $200. In fact, I have one in one of my campers. Although it does a great job keeping me warm in the coldest of winter, I seriously doubt it would stand up to the beating of full-time truck service.
In the hot summer months, nothing beats air conditioning. Especially when truckers often sleep in the heat of the day as I do.
Depending on how each particular truck and sleeper is equipped, there are several options for drivers to stay cool while sleeping.
- Idle the engine and turn on the air conditioning. This is by far the most costly option. A semi-truck can burn as much as a gallon of fuel per hour while idling, and it causes its share of engine wear. It’s also not legal in many states.
- Tough it out. Put screens in the windows and have a couple of fans running. You can get through it. I’ve been there on this one. It’s not fun.
- Use Shore Power. Truck stops with available shore power are hard to find, but a few are out there. This author believes shore power will become more available in the future, especially in warmer states. You can use an extension cord to plug in a window A/C unit.
- Have an APU, or Alternative Power Unit. The truck I drive has a separate electric heater and air conditioner. The unit is powered by a 2-cylinder diesel engine and powers all of my 120-volt needs. In my case, the APU provides heating and cooling through a roof-mounted air conditioner, much like an RV.
What Does Today’s Truck Sleeper Look Like Inside?
These pictures are of the truck sleeper I spend most of my weeks living in. I have most of the comforts I’d have at home.
- APU-powered Heat and air conditioning
- Microwave oven
- Refrigerator/freezer
- Digital television and antenna
- Comfortable twin XL bed
- plenty of storage
- Slide-out workspace
- Enough 110-volt electricity to run any household appliance
- Enough floor space for my daily workout routine.
Conclusion
As I mentioned, you can get anything they offer in a million-dollar custom motorhome built into a custom sleeper. It’s just a matter of weight, expense, and the length of your truck when it’s all done. But 98 percent of truck sleepers will fall into one of the above-mentioned categories.