Is it feasible to increase the height of the box or the size of an over-cab "attic?"

[scapegoatwax]

Hey folks!

I'm most interested in box trucks/straight trucks, and I'd really like to find one with a cutaway to the driver's cab. On top of that, I'd really like to have an over-cab "attic" to use as a 'bedroom.'

I probably won't get a used Uhaul, but this sort of build of truck appeals to me the most, so this is effectively what I'm visualizing:


Assuming I wanted to add enough height to comfortably sleep or sit up in the attic area, would that be possible? Would it be feasible? Would I want to install some extra support for the attic area?

If I'm increasing the height of that portion of the box, does it make sense to also increase the height of the rest of the box? Or should I taper back down to the original height? Or something else?

Regarding the cab cutaway, I have heard that there are "conversion kits" to make the process a little easier and reduce the margin of error. I don't mind a DIY solution, though, if it saves me a dime and isn't particularly dangerous. (Not compromising structural integrity, etc.) However, a lot of cabs either have a "middle seat" and/or a window to peek into the box. Can a cutaway be installed in these sorts of cabs?

Examples:




Thanks!

[bushpilot]

I think you'd have to be pretty short to be able to SIT up in any cab over bed.
Our coach doesn't have the (occasionally) optional 6 inch extension (were already 13' 1" to the top of the air conditioners).

I don't know why you'd raise the height in the front & not do it in the rear or all the way back - certainly aero dynamics won't suffer.

regardless of what you do - you really should keep it under 13'6" (standard height of tractor trailer Trailers) - anything over that height is gonna limit where you can fit. IE the oklahoma turnpikes are height restricted to 13' 6" (anything more and you're gonna be pealing the top off as you go under bridges).

As for the pass thru - anything is possible & they make accordion gaskets to seal the cab to the box (almost all our conversations have 'em)...if the opening were too large after the window removal some light welding and body work could finish it.

I'd remove that center seat for the freedom of passing / walking thru to the "house".

[asitool]

There are several things to consider....here are a few that come to mind

Legal maximum height is 13' 6" (it may be 14 in some states but I wouldn't suggest going over 13')

Are you using a light duty chassis or a class 8? How high is the top of the cab? A class 8 Cab roof is about 9' high, (for comparison that Uhaul truck in your pictures is probably about 9-10' at the top of the box!)

Are you going to cut the back of the cab out (leave the top intact), then put your box behind and over the top of the cab roof? In this case you'll want a flexible rubber seal to allow the box to flex differently than the cab.

If you use a class 8 truck you won't get much more than 4' max height in your room over the cab. You are also limited by how far over the front of the truck you can go. Your cab will be 4-5 feet long. If you go much further over the cab you will likely have problems with the hood not being able to open properly, (and it'll look strange!)

You could gain a few more inches by cutting the top of the cab out but you can only cut down to a couple of inches above the windshield and that brings a whole new set of limitations...and problems involving the way the box moves with the cab as the truck moves and flexes over the road.

If you're planning cutting the roof out of the cab and rigid mounting the box you'll be limited to a fairly short box (aprox 14' or less) and want to use something like air ride/air bags to allow the cab and box to remain rigid while the chassis flexes underneath.

If you are going to use a light duty truck that is lower to the ground you are now limited by the chassis and what size box it will support.

What are your goals for the vehicle and how will the room above the cab work with the rest of it?

[scapegoatwax]

Thanks for the feedback, friends!

Originally Posted by bushpilot

I think you'd have to be pretty short to be able to SIT up in any cab over bed.

I'm 6'0", so definitely not short by most people's standards! I went ahead and got some rough measurements of myself. Kneeling, I'm about 4'5" tall and sitting I'm about 3'0" as you'd expect. Of course, that's not factoring in a few inches of clearance, the ~6+" of mattress, and the insulation, however thick that needs to be. A lot of the attics I looked at seemed to be about 3 feet tall, from what I remember. (But I could be wrong!)

Originally Posted by asitool

Legal maximum height is 13' 6" (it may be 14 in some states but I wouldn't suggest going over 13')

I'd definitely want to stick to the most strict legal maximum, that way I can go wherever I want. 13'6" it is!

Originally Posted by asitool

Are you using a light duty chassis or a class 8? How high is the top of the cab? A class 8 Cab roof is about 9' high, (for comparison that Uhaul truck in your pictures is probably about 9-10' at the top of the box!)

I actually hadn't considered this specifically. I definitely need to learn a lot more before committing to anything, but here are some thoughts I've had: (Not suggesting any of these are true, and many of them are assumptions!)

• I don't actually know the "technical" difference between light duty and Class 8.
• Light duty trucks might be easier/cheaper to service? If they use "consumer" truck/van parts, those would presumably be easier to find.
• Class 8 or heavier-duty trucks might be more reliable? That seems to be an underlying suggestion in a lot of stuff I've read.
• Fuel economy isn't tremendously important to me, I don't intend to move around constantly. I don't imagine paying premium for the difference between 8MPG and 10MPG is worth it.

Originally Posted by asitool

Are you going to cut the back of the cab out (leave the top intact), then put your box behind and over the top of the cab roof? In this case you'll want a flexible rubber seal to allow the box to flex differently than the cab.

I'm not 100% I understand what you're asking, but that sounds right. If I had a square box on the back of a truck, I'd like to add an attic over the cab of my vehicle that resembles the box on the Uhaul in my first post. The cutaway between the box and cab would simply be shorter than the lowest point of the attic area, and I don't mind having to duck to move between the cab and the box.

Originally Posted by asitool

If you use a class 8 truck you won't get much more than 4' max height in your room over the cab. You are also limited by how far over the front of the truck you can go. Your cab will be 4-5 feet long. If you go much further over the cab you will likely have problems with the hood not being able to open properly, (and it'll look strange!)

4' of height sounds like the bare minimum of what I need, it's probably adequate. Depending on how much space insulation takes up, then with a mattress it's probably enough for me to sit up! Having 4-5 feet of length sounds like more than enough for me! I don't mind custom-building a mattress to fit the area and I'm a small enough person to fit on less than a Twin size mattress.

Originally Posted by asitool

You could gain a few more inches by cutting the top of the cab out but you can only cut down to a couple of inches above the windshield and that brings a whole new set of limitations...and problems involving the way the box moves with the cab as the truck moves and flexes over the road.

If you're planning cutting the roof out of the cab and rigid mounting the box you'll be limited to a fairly short box (aprox 14' or less) and want to use something like air ride/air bags to allow the cab and box to remain rigid while the chassis flexes underneath.

Cutting out the top of the cab sounds a little sketchy to me, I don't even want to think about that unless there's no other way for me to get enough height. Not sure I could build up enough confidence and knowledge to attempt that myself so it sounds pretty costly.

Originally Posted by asitool

If you are going to use a light duty truck that is lower to the ground you are now limited by the chassis and what size box it will support.

What are your goals for the vehicle and how will the room above the cab work with the rest of it?

Fair enough, I hadn't considered that this might be too much for a light duty truck...

As far as goals for the vehicle, I feel like it's pretty simple. I'm sure my needs and goals will adjust over time and this project is definitely at least a year or two away for me.

Basically, I'm hoping to end up with a custom-build motorhome. I started off looking into van dwelling and decided I personally want to upsize from that. I'm tall, and I'd like to be able to stand up, because I'm a bit of a homebody and I'd get stir crazy and uncomfortable if I couldn't stand up "at home." So, I started looking at busses, I haven't ruled them out but I've got my reservations about them. One is that most busses are too short for people my height to stand comfortably in. (Like, the inside is usually about 6'0, and after you install insulation and flooring, I'm no longer able to stand up straight!)

So, I like that box trucks have a taller area, but also the square shape seems much easier to work with and build off of!

All that said, I'd like for all of the basic amenities to be available to me while remaining as off-grid as is feasible. I want access to an enclosed bathroom with a hot shower (which I don't necessarily need to use every day, but I just don't want to live without) and a toilet (if the bathroom is enclosed and has a vent, I don't mind mostly using a composting toilet). Besides the bathroom, I'd like access to a kitchen with a sink and a stove. I like the idea of this diesel stove/heater, it apparently is pretty efficient and could technically be tied into the fuel tank but I don't know how safe/practical that actually is.

Besides that, I have considered trying to partition off a "garage/workshop" area towards the back garage door of the box. Here I could keep tools and work on projects or any odd jobs that might come up during nomadic life. Without getting into a whole lot of detail about this partition/separate room, I have some pretty cool ideas that I think will work but these ideas can get ironed out after I figure out if my bedroom solution works!

As far as things I need to store, there's not much. I have a fairly minimal wardrobe that I'm still trying to shrink down to the right size, any place with about 2 feet of a hanging rod and maybe a bin would be enough. I have a bicycle I'd want to bring along with me and have been getting into skateboarding, but that stuff all has pretty space-efficient means of being stored.

We've talked about the sleeping attic area already.

In a ~14-foot Uhaul type truck, there's not enough room for my current vision. Around ~17-foot, I think it'd be a tight fit. This is one of the main reasons I'd like to have the over-cab attic as a sleeping area, saving that floorspace really opens up the rest of the design. It's also just a design quirk that I really like.

[scapegoatwax]

Thanks for the replies, friends!

Man, I don't know what happened but I typed out a long reply to the both of you with quotes and somehow it didn't get posted. (...and it got lost...)

Regarding what I want to use the conversion for: Essentially a DIY camper/motorhome. I'd like to move into it as a permanent residence, one I can move wherever I feel like living. I got inspired by vandwelling but decided it was too small. Most importantly, I wanted an enclosed bathroom with a shower and I wanted to be able to stand up straight in my home. Busses would require a lot of DIY and they are generally short for some people, especially after adding insulation and flooring and whatnot.

So, I took a few measurements of myself and here's what I found. I'm 6'0", for reference. Sitting down, I'm ~3'0" which is probably to be expected. Kneeling, I'm ~4'6".

I don't know how much space insulation takes up, but I reckon a mattress is going to take up at least 6" of height. So we definitely need more than 3'6" of height in the attic for me to be able to have a comfortable space. Enough height for me to be able to kneel comfortably would be gravy but as long as I can sit up and not bump my head I'll be content. As far as the "length" of the cab attic, it doesn't need to be very long. 4' to 5' is more than enough. I currently sleep on a full size mattress and it's got way too much width for me, even a twin would probably be bigger than I "need." Not that I mind having the extra room! Also, I don't mind custom building a mattress as I'm pretty familiar with several different types of foam.

So that's the sleeping attic area. I really like the idea of that design, it seems like a practical use of space (if it's feasible) that would open up the rest of the box nicely.

I alluded to wanting a separate bathroom, that doesn't seem too out of the ordinary from what I've seen. I'm not opposed to using something like a composting toilet to avoid worrying about a black water tank, but I do want to be able to stand up and take a warm shower (not necessarily every day) and I do want to be able to partition off the smell of using the restroom.

In the living area of the box, I'd like to have a kitchen area with a stove and a sink. I found this diesel stove that doubles as a space heater and it seems like an elegant solution--I don't know how practical or safe it is to tie into a truck's diesel tank though. Other amenities (fridge, etc) are kind of malleable depending on how feasible mobile solutions are.

The rest of the build will kind of scale and emerge from the size of vehicle I end up with. I've been fantasizing about having a sort of workshop area partitioned off where I could store tools and work on projects or odd jobs picked up along the road. I'm envisioning this partition taking up the back area of the box near the garage door, and its length would essentially reflect the ~6'5"-6'10" area the door rolls up into. When the door is rolled up, the workshop area would kind of function like a patio for the rest of the box, and the partition could have some insulation built into it.

I don't have any particularly large belongings that need to come with me with the exception of maybe a bicycle, and if I were transitioning into this lifestyle I might spring for a motorized bicycle which would be a little larger and a lot heavier.

So that's my plans for the camper. I'm honestly not sure what kind of truck I'm looking for, though. I'm trying to research and figure that out but I haven't found very good resources for comparing things and weighing pros and cons.

I think a 14-foot truck is feasible, but it would cause me to make compromises I don't think I would be happy with. I think 17-foot is the size where I could probably downsize from my expectations and still end up happy. Regarding box height, I would definitely like to stay under the lowest legal maximum so I can go wherever I want! 13'6" it is!

Regarding Light Duty vs Class 8, I'm at a loss. I don't really know how to choose which is right for me, but perhaps talking about my expectations for size and build will help iron that out? I will say that cutting into the top of the cab to "lower" the attic sounds scary and I don't think I'd want to go that far.

Sorry if I skipped over some of your points, I wasn't as thorough or structured this second time around... thanks again for the advice!

[Bob86ZZ4]

Do you already have a truck? Todd still has his "RumRunner" I believe. And I think he would sell it for a screaming deal. The racingjunk add linked in his thread is expired but you should send him a message and see about it. http://www.truckconversion.net/forum...umrunner-7307/

[scapegoatwax]

Originally Posted by Bob86ZZ4

Do you already have a truck?

No, I don't already have a truck. I don't think I can justify buying a finished conversion, either.

I'll probably send him a message for the sake of learning, but just looking at that post it doesn't sound like I can scratch fair a fair price for what he's asking.

The rough plan in my head is to buy a fairly inexpensive truck, hopefully for around ~$5,000 or less, and from there invest money into it as I can. Not only does this let me decide how much I want to spend on it, but I can also be patient and try to look for deals and value and opportunities. On top of that, I get to do everything the way I want. (To the best of my budget/ability.)

[asitool]

What are your requirements for the truck? Do you want it to have plenty of power and be able to tow a lot? Do you want an automatic transmission? Are you looking for fuel economy?

[scapegoatwax]

The main requirement for the truck is for it to be a mobile home. I don't know a whole lot so I could be naive about a few things.

I am taking for granted that most trucks designed for moving or hauling cargo can hold the weight of a camper conversion. That's the main concern, it would be nice if I could also tow a vehicle behind it. Nothing huge, likely an electric car or a hybrid.

I have only ever driven an automatic so I have a strong preference for it. I'm not opposed to a manual, but every other aspect of the vehicle would have to be an excellent value to justify me adding that level of difficulty/learning/initial discomfort.

Fuel economy is not tremendously important, but it's obviously appreciated. I don't intend to move around a lot, my expectation is to find places I like and hang out for a while. Probably easily more than a month between moves--especially far ones.

[bushpilot]

Originally Posted by scapegoatwax

I am taking for granted that most trucks designed for moving or hauling cargo can hold the weight of a camper conversion. That's the main concern, it would be nice if I could also tow a vehicle behind it. Nothing huge, likely an electric car or a hybrid.

depends on the truck...moderately loaded we tip the scale at a svelte 36k lbs...plenty others here are closer to 50k lbs.

pulling a toad doesnt necessarily add a lot of tongue weight, but you need the torque and brakes that a larger truck provides.

obviously for comfort (and peace of mind) you don't want to max out the capacity of your truck - you want plenty of margin for safety and performance, at the end of the day not having the right truck will make life pretty miserable, if not dangerous.

nothing scares me more than to see a 350/3500 pickup truck pulling a giant (20k lbs plus) 5er....just cause the mfg says you can do it doesnt mean you should.

Originally Posted by scapegoatwax

I have only ever driven an automatic so I have a strong preference for it. I'm not opposed to a manual, but every other aspect of the vehicle would have to be an excellent value to justify me adding that level of difficulty/learning/initial discomfort.

its easy enough to learn to drive a stick - and ill tell you owning a toad that has a manual transmission is a lot easier to tow than one that doesnt.

Since you mentioned towing a hybrid - I have a friend that towed his front wheel drive Prius via a tow dolly and he had all kinds of issues (check engine light turned on, ABS wouldn't function, traction control problems & other issues)... This friend of mine is a hell of (shop owning / professional) mechanic and had quite a time getting the car back to "normal" after a short (60 mile) camping trip.

Originally Posted by scapegoatwax

Fuel economy is not tremendously important, but it's obviously appreciated. I don't intend to move around a lot, my expectation is to find places I like and hang out for a while. Probably easily more than a month between moves--especially far ones.

plan for 6 mpg (potentially less if youre using a gas engine truck)....when/if you get 8+ mpg you'll be celebrating...again its dependent on the truck.

[scapegoatwax]

Yeah, I'm not afraid of learning to drive a stick I just haven't... and I haven't needed to. I definitely wouldn't want to learn to drive stick in a box truck. haha

Interesting (and scary) those issues with the towed Prius. That's something that I'll have to research... maybe particular kinds of trailers could help combat that?

6mpg is lower than I've been accounting for, but it's still an acceptable moving cost. Might as well finance for 5mpg and hope to do better.

Does any of this info lead me towards any specific kinds of trucks?

[Bob86ZZ4]

If you are going to try to figure out how much it will cost you to build out the living quarters. Do so, then double it. And then add a bit more. That's what most of the guys that have built their own will tell you. Keep a close watch on the "359 Race Rig" thread. I haven't seen any costs there but maybe they'll disclose some ballpark figures when they near the end.

[scapegoatwax]

Thanks for the suggestion! Just glancing at that was pretty insightful.

Yeah, I definitely intend to be very liberal with my budgeting!

[bushpilot]

Originally Posted by scapegoatwax

Yeah, I'm not afraid of learning to drive a stick I just haven't... and I haven't needed to. I definitely wouldn't want to learn to drive stick in a box truck. haha

Interesting (and scary) those issues with the towed Prius. That's something that I'll have to research... maybe particular kinds of trailers could help combat that?

6mpg is lower than I've been accounting for, but it's still an acceptable moving cost. Might as well finance for 5mpg and hope to do better.

Does any of this info lead me towards any specific kinds of trucks?

A Manu-matic truck is common these days. Personally I would avoid a (torque converter type) automatic - while their strong, I never hear anyone say anything good about the gearing...and theyre gonna be REALLy expensive to repair.

Buy a stick car, or find a REALLY REALLY good patient friend that owns one and buy 'em LOTS of beer (they might need it) as payment while teaching you.

Ive taught our 3 kids and at least 3 or more others to drive a stick.

regarding the mpg, it can be all over the map and I can't imagine you'd get anything better than 6 so out of a converted UHaul or similar box truck.

I won't even tell you some of the mpg that I've gotten because it doesnt seem to be the norm.

furthering the toad discussion - flat towing is easiest, but you can't back up when youre flat towing & you can't back up w/ a tow dolly either.

A tow dolly (while smaller than a conventional trailer) is more maintenance / tires bearings, brakes, lights, etc to worry with and storage can be a concern too.

IMO a flat trailer, has only a few advantages over a dolly - STORAGE isn't one of 'em...a Flat Trailer can be reversed while hitched, but they usually are nearly double the maintain (tires, brakes) and theyre a lot less maneuverable IMO.

Don't forget to budget for tires every 5 - 6 years regardless of the miles (go price a set of 22.5 inch Michelin XZE's)

[Bob86ZZ4]

There isn't much left to most Uhaul trucks when they finally sell them. Likewise for most working box trucks. Most of the boxes on those MDT trucks are pretty flimsy too. Not very good for adding a bunch of fixtures and living quarters stuff in my opinion. And most medium duty box trucks were made for short distance in town delivery. Not over the road long haul. They aren't geared for it. Hootershaker is doing the right thing by using a real truck under his box.

[scapegoatwax]

Originally Posted by Bob86ZZ4

Hootershaker is doing the right thing by using a real truck under his box.

How can I look into these real trucks and boxes that are compatible with them? This sounds like it might be the right solution for me anyways, if I am already fighting to find the kind of box shape I want.

[Bob86ZZ4]

Well, I don't think there is a compatibility chart. But plenty of people have mounted boxes to the frame rails of their trucks. I suppose you just have to figure out if you want to do it. Then find a truck you like. Most likely you're going to have to stretch the frame. Might get lucky and find a suitable truck with a long frame.

[scapegoatwax]

Is this something that can be done with 'practically any' pickup truck just by removing the bed? Assuming it's got the capability to move whatever box and its contents are put onto it?

Or is there some sort of term for a truck that comes without the typical pickup bed, like a "flat truck" or a "rail truck" or whatever it is called?

[mr.mindless]

Cab & chassis is the light duty truck term you're looking for, but you're not going to put a large box like that on a pickup.

Medium and heavy trucks that already have a box mounted are called "straight trucks"

For the sort of conversion you're wanting to do with the passthrough to the cab, you'll probably want to look for a truck that used to have a non-integrated sleeper, so you only need to worry about making a matching hole in the box. Bear in mind for your attic thoughts that a box on a heavy duty truck chassis is likely to already be at or near the 13'6" max height. I think those uhaul trucks are around 12'?

[scapegoatwax]

Regarding Uhauls, I was under the impression they were more like 10-11', but I'm not sure where I got that number. But also, the deck height seemed like it was less than ~3' in most, which already left about another ~3' of height in the attic as a starting point...

After double-checkling, here's what I got:

• 14' Uhauls
  Top to ground height: 11' (2007)
  Box deck height: 32" (2007)
  Box inside height: 7' 2" (2007)
• 17' Uhauls
  Box outside height: 11' (2006)
  Box deck height: 32"
  Box inside height: 7' 2" (2006)
• 24' Uhauls
  Outside height: 11' (2000)
  No deck height measurement
  Inside height: 7' 1'' (2000)

It looks like they are only 11' tall (the 14' says it's 11' "top to ground"), which means--assuming it's structurally safe--it is feasible to add 2' to the height. It also looks like the deck height in most of them will be close to 32", meaning that before insulation or increasing the height I'd probably have ~52" of height for my attic bed.