I've read dozens of blogs and forums on the van conversion process, and almost all start the process by insulating their van. This makes sense, of course, because it's a lot easier to complete the insulation before the walls, floor and ceiling are in place. On the other hand, it is more efficient to do the insulation if all the holes and cut-outs for vents, fans, windows, and plumbing are figured out and completed, if possible, before the insulating process begins.
The most common starting point is the floor - installing insulation, adding an underlayment, then the flooring - before moving on to the sides and roof. For several reasons, I've decided to start with the roof instead:
The conceptual design for the internal layout is pretty much done, so I can determine where all the holes will need to be cut in the roof. On the other hand, I haven't figured out the locations of everything that will require holes in the floor, so I'll continue working on these details while I'm completing the roof and ceiling.
Tackling the roof and ceiling is a mini-project that I should be able to complete while we're house and cat sitting for Marcie's sister in Boston next month.
Blue currently has an industrial metal flooring installed that won't be affected by step ladders, paint, or hot, sharp metal shards from the roof cutting process, whereas if I install the underlayment and/or flooring, I run the risk of damaging it.
The roof layout is shown below. I plan to have two 180 watt solar panels. Nine of Cups has a total of 240 watts of solar, plus the wind and prop generators. Blue will have a total of 360 watts of solar panels, 50% more than Cups, but no wind or prop generators. We won't be powering autopilots nor nav instruments from our battery bank, but we will have a fridge/freezer, LED lights, a couple of fans, and laptops, iPads, and phones to keep charged. Based on our experience with Cups, I suspect we will be “under-solar'ed”, and will frequently have a dilemma as to whether to start the engine to charge the batteries or shut down the freezer section and/or even the fridge.
We will have an exhaust fan to cool the interior. The Maxxair fan seems to be the best available. It is variable speed, can be thermostatically controlled, and best of all, it can be left open in the rain or while driving.
The vent is for the composting toilet. It will be a mushroom type vent with a screen.
The air conditioner is still being debated. We are pretty sure we want one, but we're undecided as to whether it should be on the roof. I am optimistic I can come up with a plan that puts the condenser (the major heat-producing component of an air conditioner) under the chassis and the remaining components inside the van, resulting in a quiet, efficient A/C unit without having that big ugly unit sitting on the roof. In case that doesn't pan out, I'll leave the space open on the roof. If I do get the plan to work, I can use the roof space for an additional solar panel.
The ceiling insulation will be a combination of 1” and 1/2” polyisocyanurate insulating panels. One layer, using the 1” insulation, will be glued to the roof using 3M #77 spray adhesive, and an additional 1/2” thickness will be added in the deeper areas between the roof ribs. Any gaps will be filled with Great Stuff expanding foam. Polyiso insulating panels have an R-value of 6.5/inch.
Deciding on the ceiling type and material was painful. We obviously want it to look good. Since we have the mid-roof height van, the ceiling has to be as thin as possible to avoid losing any more headroom than necessary. Ideally, whatever I use will come in 12' lengths so one piece can span the entire ceiling, rather than having to butt sections together at the roof ribs. The ceiling in Nine of Cups is constructed of 1”x3” wood strips, butted together and painted white. We like this look – it brightens up the interior and looks nice – and I would like to get the same look on Blue. So, at this point, I am leaning towards using 1x3's. I will rout out the area above each wood strip where it passes under a roof rib so that I only lose 1/4” of headroom. What I haven't figured out is how the wood strips will merge into the headliner over the cab. I'll resolve that once we get back to Blue – or I may come up with an entirely different scheme.
That's where things stand now. On Cups, we used to use the old sailor's adage “our plans are written in the sand at low tide”, but I guess we'll have to come up with a new one for the van life. Maybe “written in chalk on the tire treads” or “written in dust on the solar panels”?