With the sill plates for all the walls in place and the floor and seat-frames in for the areas aft of the ‘bridge’, I was set to put up walls.  Now, this might seem simple, but keeping things plumb in a off-level in two direction bus with a curved ceiling is a bit tougher than one might think.

  First (and easiest) were the wall studs that were right by the outside of the bus by the window supports, because it was simple to line them up to be plumb.  And the 2×3″ lumber fit just about perfectly with the window supports.  Well, except for the seat-rail that needed to have a cut in the stud to fit up close.  And the  drilling into the studs to allow for the four screws and washer-discs that held the windows in place, though I didn’t really have to deal with those until I thought I knew what I was doing because I started right behind the aft cabin seat on the port side.

My handy Kreg jig and the official screws that go with it …

  This wall is the front wall of the bathroom, and went along one of the skinned windows.  It was a bit trickier to put in because it didn’t run along one of those support ribs, and thus I had to use a framing square to try and keep it plumb while fitting it behind the seat.  But on another note, it was east to secure, as several screws were put straight through it into the inner metal ‘skin’ of the bus, or into the pressure-treated plywood of the inside of the skinned window.  At the bottom, I used a Kreg jig to make pocket holes and then used pan-headed wood screws to the sill I had already attached to the bus floor.

Behold the wonder of the pocket jig.

  And after I had that first stud in, I realized that it was harder to figure out the others.  I ended up using some masonry line to make a straight line across the bus to the other windows so that I could get a straight line for my wall.  While I could run a chalk-line from one end of the bus to the other and mark a midline both on the ceiling and on the floor, you really can’t easily do that on the curved ceiling going from side to side.  And this is actually a big deal trying to do the studs on a 16″ on center standard.

  It’s very easy to measure on the floor, but at the top, I ended up having to use a large and a small framing square to measure out the 14 1/2″ distance from the previous stud, being sure to be perpendicular, and then measuring up to the ceiling both to mark the location and to make a measurement on how much longer the next stud would be.  And then the stud needed to have an extra angle figured in for the slope of the ceiling.

Like this …

  This wall had an added extra issue, in that the inner corner would have been right in the middle of the forward ceiling hatch. As you can see from the picture, I chose to build around it.  That’s because the hatches that they chose to add to our bus included vents that could be adjusted forward or back, and I wanted to be able to not only have these work for the cabin (and potentially the master bedroom) while still providing privacy for people in the bathroom (or in the bunks).

  But this wall was relatively easy.  In order to finish up the back wall for the bathroom, I had to deal with the wheelwell (well, at least the one on the port side, but I’d have to deal with the starboard side eventually…).  On the port side, I ended up integrating the box over the wheelwell into the wall, and then running the rest of the studs up along the galley area.

  On the starboard side, I made a nice box that would have a wall built atop it, and a doorway that would run alongside it. These

Starboard side wheelwell box.

Port side wheelwell box.

were set to be fairly tight with the metal of the wheelwells, and able to be packed with fiberglass insulation to negate road noise and provide a thermal barrier as could be managed.  You might note the crossmember over the blue painter’s tape that’s on the wheelwells – that’s the sill of yet another wall on either side of the main walkway.

Like the bathroom.

For the tops of studs.

 But the farther I went along, the easier the process got, until I had a nice forest of studs dividing the space up into phantom rooms and doorways.  One of the only real problems with these was that some of the 2×3″ boards had twists or warps, and these could make it hard to keep the walls in line. Another was that the screws at the top of the studs had to go into either the metal skin or the structural support ribs of the bus body itself.  I used a whole lot of these Teks screws, and they were ‘self -tapping’, and for the metal skin of the ceiling, they were.  However, when you needed to screw into one of the structural ribs, they just wouldn’t make it.  I ended up having to pre-drill holes for these screws, which meant lining up the stud that already had the pocket jig’s holes in them, and keeping them from drifting while I fitted the small drill in the pocket jig holes and drilled into the metal.  Not surprisingly, they wanted to slide all over the place, rather than drill a hole, and this took some practice and a bunch of drill bits.

  But eventually, I got that all done, and the space was divided, and began to look like this:

Looking from the master bedroom toward the front. Lots of walls one could walk through …

  It just doesn’t look the same as that big empty room, though it did start to give a feel for how tight or spacious a part of the bus was going to be. It certainly makes a difference to have the 3D feel of the plan.  Tape outlines on the floor look fine against your feet, but the studs really make the space feel delimited. 200 square feet can feel really small sometimes …