THE BUS CONVERSION – PART 4

The following entry discusses work we did on our bus in the fall of 2007 and is not precisely in chronological order.


The shop floor

I needed to build a new rear wall to give the bus rigidity. I wanted a door in this wall, and I wanted to lower a section of floor in between the main bus frame rails so I could have more standing room underneath the loft floor.

I used 1X2 steel tubing again to make the wall really strong and welded a new little doorway into the middle. Once this was finished I screwed strapping to the metal studs for the exterior metal to attach to.

As I mentioned in a previous blog entry, the bus floor is made from sheet metal bent into decking and bolted perpendicular to the frame rails. The frame rails under the floor have about two feet of space between them. If we could move the section of floor between the frame rails from the top of the rails to the bottom, we would gain about 13 inches of headroom. We figured this space would make a perfect lowered walkway, about four feet long, in the shop. The floor on either side of the frame rails would stay at its current level, since we were planning on filling the space with cabinets, a workbench, and maybe some appliances, like the on-demand water heater.

Once again, this was an idea that worked good in our heads before we had considered all the variables – like that the bus roof bears on the floor decking. By removing this middle section of floor, we would create a situation where nothing was stopping the rear walls and roof from sagging over the frame right to the ground. The solution was welding in a structural beam beneath floor decking on the outer edges of the bus to match the length of the hole. Then I installed angle bracing that would hold up the new beams and join them to the ends of the new lowered floor joists running under the frame rails, creating a kind of truss-like strength.

I then used a combination of reciprocating saw, circular saw, jig saw, and grinder to wrestle the rectangular piece out. This was no small task. Due to its complicated profile, the decking was difficult to cut through, and I always seemed to be catching one more piece. (At this point, I stopped with the dropped floor to build the bumper stair, which I describe in detail below.)

I carefully welded 1X2 tubing to each frame rail, creating a flat surface on each rail that I then attached sheet metal and plywood to. Please don’t blast me with comments on how I welded to the frame. I know it’s not exactly ideal, but I tacked them just enough to make plywooding possible … I will never do it again I promise!

I plan to also bolt the floor joists to the frame to conform to regulations. And I still need to caulk all the joints in the bottom of the dropped floor to seal out water and road muck. The outside of the dropped floor box, as in under the bus, will receive a coat of spray foam as a moisture barrier and insulation. The final result though, is a shop that I, at six feet three inches, can stand upright in and still have a four-foot loft above

The bumper stair

Despite lowering the floor 13 inches, we still needed some way of getting in and out of the shop that didn’t require a hard climb over the back bumper or a high jump from the ground. We weren’t interested in lugging around a step stool since we didn’t want to create space to store it, plus we still would have to negotiate the bumper. After some lengthy deliberation, we decided that creating a stair to fold out of the bumper was the best possible solution.

First, I removed the section of bumper that matched the size of the doorway and dropped floor. The bumper is bolted to the ends of the frame rails with angle brackets, and the ends toward the outside walls are held up with large pipe braces bolted again to the frame rails. This meant that after I cut out the section of bumper, two side pieces pretty much stayed right where they were.

I cleaned up the detached section of bumper so it would accept welds better. Then I welded a pair of hinges to the bottom of the bumper section. I welded the other leaf on the hinge to the rear-most floor joist. This allowed the bumper to now flip from its original position to an upside-down position. I made a small frame from some leftover scrap metal and welded this to another set of hinges on the back of the bumper.

I drilled a hole in a piece of sheet metal and welded it to the passenger side of my new bumper stair. Then I built a spring-loaded catch pin assembly that I attached to the bumper just beside the stair section. Now the pin would fit into the hole I had drilled in the sheet metal, holding the bumper stair in the closed position. When the step is folded up and pushed shut, the pin slides into the hole in the bumper stair and locks it into position. To release the bumper stair, I simply pull a knob attached to the spring pin, allowing the stair to flop down into its easy enter position.

I built the catch pin assembly because I could find nothing that would work off the shelf. My homemade version works, but it sticks a little. On a later visit to Princess Auto I found a surplus catch pin assembly that was fully housed and much better quality, so I decided to eventually replace mine with the new one. The door that I will one day install in the back wall will swing out over the bumper stair so a person can open the door then release the stair and leave the skoach easily and safely.

Injury number three

As I was working on removing the floor, a spark found its way behind my glasses and into my eye. These little shards of metal were becoming a nuisance. The next morning, I went with my father-in-law to Brandon Hospital. While he visited his ailing father, I sat in emergency waiting, once again, to get medical treatment as a result of the bus. That made three.

I started chatting with an older couple sitting beside me, and we quickly got to the topic of bus conversions, thanks to my eye injury. Surprisingly, they also had a bus conversion, a coach, though, and it was for sale –a real deal at $80,000. The man told me that when he hired a bus conversion company to install the master bedroom, he was surprised to get a bill for $50,000. He added that this covered everything, however, including the blinds. We expect to convert our bus completely for 10 grand less than his bedroom cost him … I can see how pro-built conversions easily surpass the million-dollar mark!


Windows

The steel 1X2 extensions that I had welded in when raising the roof were half completed, as I had left out those that interfered with the window openings. Now I created the rectangular frames for the each of the windows then welded my extensions into the U channel supports above and below the window openings. Finally I welded the extensions to the tops and bottoms of the window frames.

A word on windows. From the beginning of our project, we’d had many discussions about what kind of windows we wanted in the bus and quickly decided that residential windows would never work.

A residential window is essentially a box housing a piece of glass (a.k.a. window jamb) with trim, often called a brick mould, applied on the front of the box. The window is installed into the rough opening and pushed into the house until the brick mould makes contact with the outside of the house. Then nails or screws are driven through the brick mould on old wood windows, or, on newer vinyl windows, through the nailing flange attached to the brick mould. Then the space between the window jamb (the box) and the framing creating the rough opening is filled with some type of insulation, whether fibreglass or expanding foam. Finally, interior trim is applied to the window jamb on the inside, covering the gap between the jamb and the framing and completing the installation.

People converting buses need to be aware that, despite residential windows being readily available and comparatively cheap, their installation requirements make them unsuitable for a rolling home, not to mention their bulky, cumbersome look. RV windows, on the other hand, are similar to residential windows in that they have a flange or brick mould resting on the outer surface of the RV wall; however, this mould isn’t nailed or screwed to the structure. Each RV window is shipped with an aluminum flange, called an installation ring, which is screwed to the window jamb on the inside, similar to interior trim on houses, causing the window to pinch the wall. Push the window out and the installation ring prevents the window from moving away from the bus. Go outside and push the window in, and the flange, or brick mould, stops the window from falling into your RV.

Why the difference? Well, one simple reason. The body of the RV twists, bends, and flexes as you travel down the road, more than one might realize. Most modern RVs are not much more than 2X2 wood framing glued and stapled into place, hence the term stick’n’staple used to reference the modern mass-produced RV. So if windows are physically bonded to the body of an RV, they might start exploding as the RV drives down the road. Mind you, if you drive through parts of Greater Vancouver where there are daily drive-by shootings, you may find your windows blowing out anyway, but I digress.

So we knew we wanted good RV windows, but our research suggested we avoid, if we could afford to, single-pane windows, which “sweat,” meaning they build up lots of condensation as the humidity rises in the living space. Not to mention that single-pane windows lose a lot of heat, whereas double-pane windows are better insulated. Houses have air exchange units and use double-, triple-, and sometimes quadruple-pane windows for these and many other reasons. We read a story on the net of one guy who had to mop the floors of his bus every morning because there was so much water. This was not acceptable to us, so we got to work looking for good, quality double-pane windows.

I also need to mention that in my experience as a carpenter, windows are ordered before the framing even starts, often before we even break ground for the basement. So I, thinking in the only way I knew, believed the same process was applicable here.

In October 2007, we found a company in Summerland, BC, that custom builds RV and bus conversion double-pane, high-quality windows. We had a choice of black or white trim, and that was easy – black. And we had a range of choices for types of glass – clear, tinted, or solar reflective. They also offered several different styles of window – solid, sliders, and T-sliders (upper is solid and bottom slides). We finalized our floor plan, or so we thought, and made a list of our somewhat randomly chosen window sizes, sending them off to Sun-View Industries, along with a cheque for $2,911.58. Ouch! We decided on solar reflective for the locations where we wanted privacy, tinted for three small windows we choose at the last minute, and clear for the rest. A month or so later we received our 10 windows. Unfortunately, somewhere between Summerland, BC, and Moosomin, Sask., where Jay’s Moving and Shipping delivered our windows, the outer flange on one end of the longest window, which stuck out of the top of the crate, was crushed. That window alone was $366.50. After a long battle with Jay’s, we finally got them to compensate us for the damaged window.

Unfortunately, ordering the windows this early in the game has been (so far) our biggest mistake. In fact, I have already had to move some of the rough openings to improve sightlines and solve other design issues. We are glad we went through the headache of changing them, but if we had done a more thorough job of planning from the beginning, these issues wouldn’t have been issues. Nor would we have had to further limit our design, which is constantly changing, because we wouldn’t have a stack of really expensive windows ready to be installed.


Strapping

With the rough openings installed, it was time to prepare the exterior of the bus for sheet metal. This meant applying wood to the outside of the bus so that when the new sheet metal skin was applied it would able to go over the bumper rails (black strips running the length of each side of the bus). We didn’t want to remove them as they provide valuable strength and integrity to the structure of the bus. I started by cutting 1X4 boards down to 1-¾ inches and planing them down to about 5/8 inches. I screwed the strapping to the bus in rows, starting at the top of the bus and adding a new row every two feet down. Our windows have round corners and our rough openings had square corners. So I built special corner blocks to screw to the corners of the rough openings so that the windows, once installed, would have support all around their circumference.

I had planned on putting this strapping around all windows and every edge of the exterior walls. Many months have passed since I did this work in December 2007, and as I have had so much time to think about this strapping idea, I am seeing many holes in the theory. First, if we want to attach anything onto the bus, like an awning or bracket or whatever, then I would only be able to do so where there was strapping behind the sheet metal. If anything slightly sharp bumped the sheet metal, it could puncture the exterior wall. I am starting to lean toward removing all this strapping (luckily I only had only done it on the passenger side) and installing plywood and then a waterproofing membrane over the entire exterior of the bus. This would make the bus much more solid, it would give backing everywhere, and it would make screwing the sheet metal on way easier. And perhaps it will help with sound and air flow transfer. It seems we have to do many of the jobs on this bus twice to get them done right.

Next time: interior framing and floors.