Tools:

Materials: 

Floor Insulation

We chose to insulate using XPS (standard pink/blue foam board insulation) because we had a source for as many free sheets as we needed. XPS is water resistant and provides excellent R-value. XPS also has high compressive strength, making it strong enough to use directly under the subfloor.  

If it weren't for our free source, we would have chosen Polyiso foam board insulation. We definitely would NOT have glued Reflectix all over our van walls. Please research and understand radiant heat before making the Reflectix mistake. 

We chose 1/2" XPS for our flooring insulation.

To Start, we used the original factory subfloor as a template to trace the cutout sizes for our floor insulation. We then sprayed Great Stuff Foam onto the van floor and laid our foam board cutouts on top. The Great Stuff works as an adhesive to secure the foam board to the floor. It also expands to fill any air gaps around the floor ribs.

Once we laid each insulation board, we piled them with heavy items we had on hand to hold the boards in place while the foam expanded overnight. 

The next morning, we cut away all of the excess Great Stuff using a serrated steak knife. 

Subfloor

For the subfloor, we used 1/4" plywood. We again used the factory subfloor as a template to trace and make the cutouts. We also staggered the cutouts of plywood on top of the insulation cutouts to keep the seams from lining up. 

To explain further, we started the floor insulation using a full 4'8' sheet in the back half of the van floor. (you can see this in the photo above) For the subfloor, we started with a full 4'x8' sheet in the front half of the van floor. Staggering the seams helped to keep everything flat for our flooring that will be laid later on. 

We secured the subfloor using flat headed, self drilling screws, straight through the metal van floor. We were careful to check that each screw location did not interfere with anything underneath of the van.

Wall Insulation

We applied Kilmat sound dampening on any of the large flat sheet metal surfaces of the van walls.

 

For insulation, we used 2" thick XPS on the large "window" sections and 1" thick everywhere else. Once all of the large open spaces were filled, we sprayed Great Stuff Foam into all of the nooks and crannies. 

We do recommend reading up on expanding foam causing wrinkling of van body panels. We have not had any issues whatsoever. However, there have been reports of people overfilling the blind cavities where the foam doesn't have enough room to expand properly.

Ceiling Insulation

We added Kilmat sound dampening to the ceiling panels.

Using Loctite power grab, we glued 1" thick XPS to the ceiling. To hold the foam board in place while the glue dried, we used scrap wood and car jacks.