Roof Racks/Deck... Side mount vs. roof mount?

[TygerCub]

I'm trying to plan budgets for a roof rack/deck and decide on the method of construction. So far, I've seen three methods of building decks. The most prevalent construction method seems to be welding square tubing directly to the window supports/bus ribs, then running more tubing across the roof as framing for a roof rack/deck. But there have been a couple of images on the web of wood decking mounted directly to the roof, and one showing the mounts on the curve of the roof using a hinged tubular arrangement.

SQUARE TUBING WELDED ONTO WINDOW SUPPORTS
PROS - Material availability and ease of construction. It's been a few years, but I can weld well enough to tack something in place, and with a little practice am sure I could weld the square tubing onto the bus ribs (and there are plenty of ribs to practice on! ). I want to use expanded steel for the deck to lessen the weight and keep the rain from pooling on the deck surface.
CONS - I'm not crazy about the looks of the supports welded on the sides. I can get creative, but would rather keep it as simple as possible.

LUMBER DECK DIRECTLY ON THE ROOF
PROS - Material availability and ease of construction. I can do this! I've built plenty of decks. Laying a couple of 2x4 pressure treated lumber down as supports, or even cutting a 2x12 to fit the curve of the bus roof line wouldn't be difficult. Time consuming to template and cut, yes. Difficult, no.
CONS - Maintenance. I don't like the idea of having to weather proof all that wood. IMHO, that's one of the worst things about a wood deck. And the periodic maintenance of pressure washing/resealing is a real mess!

SPECIALTY FITTINGS FOR METAL DECKING
PROS - Sleek design. I really like the looks of this style of supports. It's different, looks like part of the bus design, and appears easy to install.
CONS - Not sure of the strength of all those hinged joints over time. What are the supports called, and who can they be purchased through? What is the overall strength of that type of system? Can it be easily matched to a expanded steel decking?

So after all this rambling, my questions are: What type of deck did you use? Why? And are you still happy with it?

[The Eggcrate]

Well, I haven't built my roof deck yet, but I've been collecting materials for awhile. I went to a junkyard where an old firetruck had some aluminum beams for decking on the top. They are very very sturdy, measuring 2.5" by 0.75". There is a total of 202' for me to make a very nice frame for the deck and all of the supports necessary. I'm going to cut the legs to fit the curve of the roof about a foot in from each edge of the bus, and weld a curved flange to the leg to bolt down to the roof. I am still undecided as to the cheapest, sturdiest option for the the actual decking on the roof. I was thinking that I might be able to find a stack of retired road signs for the job, keeping everything aluminum and very stiff, for little money. It would be pretty unique too, leaving all of those signs face up on the deck. I would need between 12 and 24 depending on the size for full length coverage. I plan on leaving the hatches in use with a ladder in the rear. There will also be a ladder on the outside of the bus at the back.

[elkoskoolie]

I've always thought the rails from aluminum outdoor bleacher seats would make an excellent, light weight, sturdy/strong maintenance free deck. Trouble is, where the heck do you find them?

[swhite832]

"The Roof Rack"

I have thought long and hard about this because the roof rack is the main reason I bought a school bus. I have been researching this issue for awhile. I have seen many and been on only one. Factoring in material cost, labor, and durability I think My deck will be something like this;
http://www.skoolie.net/gallery2/v/Skoolies/TeamBAT/

Decked with this;
http://www.eplastics.com/Plastic/ABS-Te ... stic-Sheet
Or this:
http://www.eplastics.com/Plastic/Fiberg ... uded_Grate

There is minimal fabrication, no angles or curves, and strength in the form of truss type construction. I need the truss beam to carry weight over roof supports I have to remove to accomodate windows. I could probably work around that but it gives me the ability to get back to dimensional products.(which this bus isn't)and I may be able to hide the exposed bolts on the interior. It also provides shade to the roof(a major plus). It is unknown how slick the decking may be if wet. I will order samples.

I have seen Eggcrate's method in action and it is very "clean" looking. While I do not believe it to be as strong as connecting at the vertical portion of the supports closer to the windows, in my opinion, it is adequate. The only reason I will not be doing it that way is the increased labor I believe it will cause. It does look better and if I didn't have 14 irons in the fire i would probably do it Eggcrate's way.

I do not understand what you mean by specialty fittings for metal decking? Is this something that can be sourced already made or does it have to be fabricated?

I really do not like the idea of wood, asthetically speaking. It seems it would be excessively heavy, bulky and would eventually hold water.

[Sojakai]

Have you considered using that Composite Decking stuff? I once saw it used on 'This Old House' and from what I can remember, they claimed that it was about the same weight as wood but was uv resistant plastic and wood dust. Had the external texture and look of wood, and came in a handful of colors.

After looking at those fittings for the rails, I got an odd idea. If you get a set of those mountings mounted at the top and another at the bottom of the windows, Could you use those to raise the roof up and keep it in square/true shape long enough to raise and weld in new supports? I guess the extra piping afterwords would be cut down for building the deck frame itself, and outside ladders and such.

[TygerCub]

I've seen the composite decking material used on housing projects that later started to deteriorate in the sun. Not too pretty. Not as bad as a wood deck, because there's less warping. But it does get a kind of peely / powdery texture that you can't do anything to fix. And, that stuff weighs a ton. It's about the same weight as fresh (wet) lumber. But unlike new lumber, it won't lighten up as it ages. Plus, it needs supports set every 12" to prevent sagging.

I really like the idea of this type of fitting (apologies to Sean for pointing so many people to his site):
http://seanf.smugmug.com/gallery/962...64_wZrRK/Large

It appears to be able to be set on the curve of the roof. my idea was that the cross-beams that support the decking material (in my case, expanded steel deck grating) could be bolted to this system and the edges cantilevered to the full 8' width, making the deck appear to float over the bus.

Another similar idea that would require a bit more welding can be seen on "Randy's Blue Bird".
http://www.skoolie.net/gallery2/v/Sk..._/013.jpg.html

I really like this arrangement too because it appears to be more solid over the long term. No hinges to weaken over time. And, depending on the skin of the bus, this type of framework can be made out of either aluminum or steel to prevent any cross-metal corrosion that may happen (there's a scientific name for the corrosion, but I can't think of it right now).

If I become pressed for time, I may just say the heck with it all and make the framework at the windows like this image:
http://www.skoolie.net/gallery2/v/Sk..._1552.jpg.html
But honestly, while I don't mind the look of this style, I think it uses more material than necessary.

Tomorrow, I go look at another bus. This time, it's a shorter, snub-nosed vehicle with a Cummins 5.9 and Allison AT545 tranny.
Wish me luck guys!

[TygerCub]

You're right about the rust. Hadn't thought about that. (bummer). Guess I could also spray a rust-cote product on it, but time and use will eventually wear that off. I donno, though. There's a lot of the expanded metal decking used at work, and I don't see too much rust on those... but that could be because they're in constant use and the distance between the deck and floor below is great enough not to show how much rust is dropping (30' or so to the ground).

So what kind of decking material do you guys use? Marine grade plywood? Aluminum deck plating? Something else?

Obviously, I've seen the traditional wood deck surface. How has that withstood time and use? Has anyone had to resurface a wooden deck on their bus yet due to weather damage? How much of a PITA did that turn out to be?

[SeanF]

Hi-

I like my roof deck, but it is probably overkill for what it does.

First, some numbers: The planks are 2"x6" Trex, which is 3.3 lbs per linear foot. I have about 400 linear feet of it up there, which added to supports, etc goes about 1500 lbs total, probably $2k in total pieces and parts.

I think there is a huge benefit during the summer months from the shade provided by the full-length, full-width deck. I also think it will help the roof paint last longer. Lastly, the Trex wears & ages very well....it looks better than the day I installed it.

I also think i could have done it lighter and cheaper, since I don't really need the entire surface to be so robust. Doing it all over again, I would have done a catwalk (either along the center line, or to one side), and then used lighter materials for the rest of the surface. I have two cargo containers up there (Thule or whatever they are), along with (4) 120-watt solar panels, so there really is no need for all of the Trex. I would look at lighter (hollow?) composite decking, aluminum bleacher seats (expensive when new, rare when used), or expanded metal with the smallest holes/most metal. Or even metal roofing?

Cheers
Sean

[paul iossi]

some other options for a roof deck would be, extruded aluminum like they used in some of the old uhaul trucks, or galvanized perforated catwalk decking.
google some of the industrial hardware companies like graingers, austin hardware, mcmaster/carr etc. also look at thomas.net

[aimsworthy]

Hello!

Would you mind telling me what the fittings are called that join your roof racks to the side of your bus? Do you think they would work without your wood reinforcements?

Thank you!

Adam

[Elliot Naess]

10-4 on shading the roof of the bus, with an air gap between the shade and the roof. Makes a big difference in interior temperature under a hot summer sun.

[unbentcrayfish]

This might be a stupid question, but it seems that all the roof decks I've seen are supported by the vertical window strips. Is it structurally sound to attach one's deck directly to the roof? (with wooden/metal beams going across the width riveted/bolted down to the roof) I plan to have lots of storage on the roof along with a drum kit and wonder if the weight would be an issue. Thanks for the help!

[Elliot Naess]

Hey, there! Welcome to the forum!
The window pillars continue over the roof, and they are quite strong.

Essentially, the body consists of a number of U-shapes that are up-side-down, beginning at the floor on one side and ending at the floor on the other side.

To these, are riveted sheet steel on both sides, except where the windows are.

So, you can put bolts thru the middle of these anywhere you like.

The U-shapes are themselves kind'a U-shaped... no, closer to Omega-shaped, but squared off. We call that a "hat section" because it resembles a hat. Remove a window or two, and you will be looking at it.

[turf]

you just need to size the cross members of the deck to keep a minimum deflection for the span of the bus.

use this calculator to see how much a particular tube will flex. if you keep deflection less than .25" it will be strong enough to what ever rated deflection per arch.

if the math says 500lbs load with <.25" deflection, that would 500 lbs per support. if you 2000lbs of gear, it'll have to have 4 joists.

you can change the size of the tubing or the gauge of the tubing to find the size that works for you.

Deflection Calculator for Square Tubing

[pepepito]

I like this idea.

[Meddle]

pepepito, I was thinking of supports exactly like you are doing. Did you form the curved profile yourself? If so, how? If you paid to have it done, how muck did it cost? That is going to look really clean! I love it!

[EastCoastCB]

Originally Posted by pepepito

I like this idea.

Now THAT is BADASS!

[miltruckman]

The specialty fittings i think you are talking about are available from McMaster Carr Co. in Chicago, IL.

Bill
Michigan

[pepepito]

Ohh I'm not taking credit for that, I took those pictures from a facebook group Canadian skoolie conversion, the guy paid someone to make them I found the idea pretty good that is why I save them.

I was thinking that putting a plate behind in the inside of the bus could help for support and to be able to unmount if necessary because welding it will definitely burn through.

[Tango]

Those are seriously heavy duty, but do not appear to be designed to attach to the roof ribs. I am working on something similar that will mate directly to the ribs which will not require spreading the load out the way the ones in the pick do.