Hi all. 2019 Promaster 2500 159", currently bare. Looking for opinions on mounting ceiling panels. The cross ribs are annoyingly unevenly spaced, which would lead to strange panel widths if screwed into firring on those ribs. One builder recommended placing evenly spaced ribs on the roof, built from expanded PVC, secured with strong marine urethane adhesive. In the Promaster, this means expanded PVC 1 inch thick, which is expensive. So, why not jsut use the urethane adhesive to affix 3" wide strips of 1" thick wood to the ceiling steel, and use those to attach the interior ceiling panels (likely 1/4" plywood, or 3 mm)
On a separate note, we are just back from 18 months in New Zealand, a good part of that in campervans. A unique feature to NZ housetrucks is people put woodstoves in them - quite a site to see a housetruck lumbering down the road, wood smoke coming out of the stack! How come no one does that here?