It's been brutally cold here in New England, but we've managed to continue work on Blue. Any project that involves adhesives or paint isn't practical in these temps, but one project that we could get done was to build the ceiling header. We've had lots of time to think about it and had several criteria for our new header:
We have the mid-height Transit, and I cannot stand up fully under the roof bows as they are, even without a header. Thus, one criteria was to make the header as thin as possible so we wouldn't lose any more height than necessary. In addition, since I seem to be becoming a little shorter with each passing year, if Blue doesn't lose too much more headroom, I am optimistic that I may be able to stand up inside in a decade or so – assuming I'm still standing at all.
The header needs to be removable. I have no illusions that I will plan this project so well that I'll never have to add, modify or repair the wiring located above the header someday.
It should be easy to clean and maintain.
It should be lightweight and/or modular so that the two of us can install it.
It needs to be flexible enough to conform to the curved ceiling profile.
What we decided on was a support of 1/4” plywood, screwed to the roof bows. This is flexible enough to follow the curve of the ceiling, but stiff enough to prevent minor rippling. The width of the ceiling was 56”, so I cut two pieces, 56” x 48”, and one piece that was 56” x 32". These were small enough for the two of us to handle.
For the visible part of the header, we chose a 1/4” vinyl tongue-and-groove planking intended for wainscoting, reminiscent of Nine of Cups' header. These come in packages of three sections, each 7-1/4” x 8'. The plan was to attach the plywood to the roof bows, butting them together, then screw the planking to the plywood. So that everything would stay firmly secured after years of road vibration, yet removable if ever necessary, I chose to use T-nuts in the plywood. To install a T-nut, a hole is drilled in the plywood large enough to fit the shank of the T-nut. It is then inserted into the backside of the ply and tapped into place with a hammer. A machine screw can then be threaded into the nut from the opposite side. I planned to use T-nuts inserted in a 5” wide by 48” long piece of plywood as a backing for the butt joints. Then I would use T-nuts spaced in rows about 18” apart to secure the tongue and groove planks to the plywood.
The process was as follows:
I installed four Rivnuts in each roof bow for attaching the plywood supports. Rivnuts are great for attaching bolts to the sheet metal of the van. They are inserted into a hole in the sheet metal, then, using a special insertion tool, are crushed against the inside of the hole. Once the tool is removed, a standard bolt can be threaded into the nut. I used Rivnuts designed for 1/4-20 bolts with a grip range of 0.020” to 0.280”. What made this part of the project even easier was that the Ford Transit has holes already pre-drilled in the roof bows that are the right size and in the right position. The part numbers and sources of the Rivnut and tool are listed below.
It would be easiest, most accurate, and about 40 degrees warmer if I could construct the entire header on the basement floor, then dismantle it and install it in the van. Before I could do this, however, I needed to check the fit of the support sections to the roof bows. I measured and drilled the three sections of plywood to fit the Rivnuts that were installed in the roof bows, and made the cutouts for the roof fan and toilet vent. Then I temporarily attached the backing plywood to the butt joints of the center section, and with Marcie's help, installed the support sections in Blue to make sure that the holes lined up with the Rivnuts, the cutouts were in the right places and that the three sections fit alongside each other. Before removing them, I carefully marked the alignment of each section with each other and the backing plywood. That way, I could reconstruct all three sections on the basement floor in exactly the same positions as they were when mounted to the roof bows.
Everything was moved inside and I began making the butt joints. I laid out all the plywood on the floor and, using the marks made previously to align everything, drilled pilot holes where each T-nut would go. Then I re-drilled all the holes to the proper size, installed all the T-nuts and screwed everything together.
Next, I cut and positioned each of the tongue-and-groove planks. Once I was happy with the fit and placement, I drilled pilot holes for the screws that would hold them in place, then took the whole thing apart once more. I re-drilled all the holes to the correct size and installed the T-nuts in the plywood. I wanted to use flat head stainless machine screws to attach the planks to the plywood, so all the holes in the planks were not only re-drilled to the correct size, but were countersunk so the screw heads would fit flush. We bought a quart of 'Oops' paint at Home Depot, and Marcie painted all the plywood a sunny yellow color while I was drilling the planks.
Everything was assembled on the floor one last time to check the fit. The final step was to measure and drill the holes for the LEDs, then it was all disassembled and carried out to Blue.
After all this prep work, installation in the van was simple and quick, except for one teeny little glitch. After measuring, re-measuring and checking the position of each LED three times, I managed to misinterpret one of my marks and drilled the hole in the wrong spot. Fortunately, I had an extra plank, and it didn't take long to cut and drill the replacement.
After installing the bezel around the fan and the LEDs, we were quite happy with the look. The combination of the 1/4" plywood and the 1/4" planking only dropped the ceiling height 1/2". I don't know that I'd do it differently if I were to do it again – except maybe drill all the LED holes correctly the first time.
The total cost, including the Rivnut tool was about $275.
Rivnuts, 1/4-20 thread, Grip range: 0.020”- 0.280”, Part No: RN2520280PNB from Jay-Cee Sales & Rivet, Inc. Cost: $67.31, including shipping, for 100. I used 20 for the roof bows, plus 5-6 that were used for practice and the learning process.
Rivnut tool: Wrench-Drive Rivet Nut Installation Tool for 1/4"-20 & 1/4"-28 Thread Size, Part No: 96349A305 from McMaster-Carr Cost: $29.84 (Plus shipping)
T-nuts: I bought these on Amazon and used about 85 at a cost of $11/100
Planks: Veranda Prefinished Reversible Vinyl Planking. Each package contains 3 pieces, each 1/4” x 7-1/4” x 96”. Four packages is just enough to do the job – if no mistakes are made. I actually used 4-2/3 packages. Available at Home Depot for $25.97 per package.
Plywood: 1/4” x 48” x 96” underlayment, 3 sheets. Home Depot at $14.16/sheet
Screws: ¼ – 20 x 3/4” stainless flathead machine screws. I used 105 at a cost of $14/50.