Part II of our Ram Promaster insulation highlights the floor and how we tackled the project. Check out how we insulated the walls and ceiling of our Promaster here.
Insulating the floor of our Ram Promaster was a pretty straightforward procedure. The only unknown piece of the puzzle was removing the factory floor, something that I wasn’t very keen to do. The floor is quite nice, and we wanted to use it as our finished flooring. Keeping damage to a minimum was a top priority.
Removing the factory floor actually wasn’t too bad. We took our time prying up little sections, moving from side to side and supporting the floor as we went worked well. Having a long 2×4 was the most valuable tool to have for the removal.
The hardest part of removing the floor was actually getting it out of the van by myself, I’d highly suggest having someone help you for this step.
The level of damage to the factory floor was minimal, I’m calling this a success! For reference, it took me about 45 minutes to get the floor out of the van.
Moving on to the insulation, we decided to continue using 1″ polyiso like we did on the walls and ceiling. We went back and forth between 1/2″ and 1″ multiple times, in the end the 1″ won out. We calculated that we’d still have about 6’2″ of headroom once everything was finished inside the van, which is adequate for us.
The best part about removing the factory floor was that we now had a template to use! Tracing the polyiso was a breeze and made for a nice fit inside the van.
After test fitting the insulation, it was time to secure the pieces down. We went with Great Stuff Pro for the job. We like that it’s a very good adhesive, it helps fill in some of the gaps and low points in the floor, and that it doesn’t set/cure instantly. After everything was foamed up, we put as many heavy things as we could find on the polyiso to hold it in place.
Following the foam it was time for the 1/4″ plywood. I’m not sure if this layer was completely necessary, but I’m glad I did it. I wanted the piece of mind of another solid layer to screw into and add support. We basically followed the same steps as the polyiso above; trace, test fit, adhere with foam, and add weight.
If you plan to use the factory tie downs, don’t forget to cut out holes before you glue everything down. I don’t know if I’ll use them in the future, but I wanted the option. I also like the idea of them helping to the hold the floor in place. You’ll need to get longer bolts to use the tie downs. I went with M8-1.25 x 60mm bolts.
The final step is to put the factory floor back in, which was easier said than done. This time my lovely assistant was around to help me wrangle the beast. I wasn’t able to snag any pictures of the process, probably because we were getting owned by the floor, but we followed the same steps as before; spray foam, weight, and then wait.
The final product! It’s kinda sad that to the untrained eye nothing has changed, but it felt like a very productive 7 hours!
- Take your time prying up the factory floor, a couple minutes isn’t worth potential damage
- Use the factory floor as a template!
- Run the polyiso and plywood in different directions, you don’t want the seams to line up
- Make sure everything fits before you glue it down
- Don’t forget longer bolts for the tie downs if you plan to use them
- Find someone to help you with the floor removal
- Two polyiso rigid foam boards
- Three sheets of 1/4″ plywood
- Six longer bolts
- Two cans of Great Stuff Pro Gaps & Cracks Sealant
- One Great Stuff Pro Gun
- One can of Great Stuff Pro Gun Cleaner
- One box knife and extra blades (I think this style would work better than what I had on hand)
- Tape measure
I have promaster 3500 extended
I need to floor removal and everything. Where are you located. please contact with me
We’re located in the greater Seattle area. If you follow write up I have full confidence in your ability to remove the floor!
I appreciate that you document the removal of factory floor so well. I have the exact same factory wood floor in my new van. Did you use only the short hand tools to pry the wood floor from the van floor? Do you think a longer flat tool will facilitate the removal with minimum or no damage. Was the factory floor glue down to the van floor well. I hope not.
Hi Chen, sorry for the very slow repsonse, we’ve been busy working on other projects.
I used the tools available to me at the time to remove the floor. This included a bike pedal wrench (the blue handled tool in the pictures), a couple scrap pieces of 2×4’s and a milk crate. The floor was glued down but with some patience it came up relatively unscathed. One idea is to wait for a very warm day to help soften the factory glue, this is just a guess, but I think that might make it go a little easier. Good luck!
Hello Im curious if you put any insulation or noise dampening in the ceiling above driver and passenger in the upper cab area? This winter in Utah I had a lot of frozen moisture stick up there then thaw. That thawed when the -26 made it to over 32 and started to drip out thru the overhead lights. Im hoping to pull that area loose and stick 1/2″ shop floor foam up there to avoid the thermal transfer and rain in the cab.
Hi Jay! I did in fact put insulationg above the headliner. I used regular fiberglass insulation for the job and it worked quite well (it’s amazing how hot it gets up there in the summer). We’ve not had the van in colder temps than the low teens but we never had condensation issues like you described. Do you have a fan? We crack our, even during sub freezing temps, to help with condensation. It seems a bit odd to leave it open during the winter but I think it help. Good luck!
It was -9 in Utah and with a propane Mr Buddy heater the moisture condensed in the upper cab and froze then thawed and started to drip. It was so cold I did not want to run the fan and suck the heat out. I now have a diesel heater to deal with extreme cold temps. and 4ft 12V seat heaters under the bed to warm the bed up from the house batteries.
I pulled the fasteners at the edge of the cab head liner and sprayed rubberized under coating on the area where the upper cab marker lights are wired and slid some thin rubber mat in as extra insulation. The area is taped tight to the 1 1/2″ insulation covering the remainder of the roof. Which also has a strong moisture barrier plastic across the roof and walls.