Making the BEST Insulated Subfloor for my Ford Transit Van Conversion (PT. 2) 

Thank you! 🥰

Thanks!! And you are super welcome!

Thank you! I thought it made a lot of sense too! 😉 It's held up absolutely rock solid, even unfinished. Still zero squeaks!

Thanks Ashley!!

Thank you, thank you! 😊

Thank you Ahmad!! It's a bigger compliment than you might guess to hear that you appreciated my honesty.🥰

Second this. Nothing is worse than a video that doesn't share the struggles for the viewers to learn from. I also love how you explain why you do many things you do because, for whatever reason, I can not blindly follow directions without knowing why I am doing something. The only knock I have on your videos is the height that it has set my wife's expectations for my work :D. You have some skills I could only dream of possessing. Thanks for sharing your knowledge!

You are so welcome! And you can totally do it! All you need is a plan and a lot of patience!

Meh, plans are overrated. 😉

Thank you!!

I'd be hesitant to use wood 2x2's, but if aluminum isn't an option, then the only other point I'd suggest changing is going up to 2" foam board since you'll already have the space.

The thermal bridging seems to be about a 1-2° (F) temperature difference as measured with a lazer temperature reader aimed directly on the heads of the screws I used to attach my plywood floor to the aluminum rails vs measuring the temperature of the plywood floor surface in the middle of two aluminum rails. Thermal bridging is much less of an issue vs the overall insulation of your entire system.

Hi Francois, concerning the adhesive, I already had some leftover from my flarespace project, but the reason I ultimately decided to use it was after reading the data sheet for Seal Bond 105 they clearly state it is safe to use with foam board, and I my concern was some adhesives can cause a chemical reaction with foam and will dissolve the foam.

Yeah, my thoughts exactly. I think in the best case scenario the wood will just take a long time to rot, but in the worst case scenario it could be a disaster and rust out your floor. I figure the fractional amount of insulation gained wasn't worth it in the end, and instead people should probably be using 1.5" think insulation board instead of the 1" that seems to be the defacto choice.

@@ErikJohnson2020 By the way, nice work area you got there, it's not like I have to build my van on the street, but nothing close to your shop.

Lol, it's hardly "my shop" - I'm just allowed inside.

Hi Scott! I haven't yet finished the sliding door step, however, I plan on making a custom plywood lining for the step, and then a storage cubby underneath the kitchen galley overhang. If you want to do something similar, you won't be able to reuse the plastic cover, or at least you'd have to cut/modify it, but it seems to me it'd be a better finish to make your own ply box and use angle aluminum for the edge treatment, and some kind of waterproof grip tape for the finished surface.

Hi Kelby! Glad you enjoyed the videos! I purchased my aluminum tubing at a local metal shop called "Metalmart", but I'm sure most cities have something similar that tradesmen use for construction jobs. As for the thickness, I'd recommend going with 1/8" thick (0.125), so that your screws have some meat to bite into. On a second trip (didn't purchase enough 1st time around) I mistakenly purchased 1/16ths and that technically also worked but when you're drilling the pilot holes, you can honestly tell the difference, and I felt more confident in the 1/8th.

@@ErikJohnson2020 Thanks! Keep you the good work.

As mentioned in the summary I'd use 1.5" Aluminum rails and foam boards rather than 1", and I'd make sure to use Polyiso foam boards and not polystyrene boards of I was to do it all over again.

None whatsoever. Just make sure your predrilled holes are somewhat smaller than the screw shaft diameter.

I won't finish the thresholds until I put in the finished floor, but I'll be putting in a metal edge guard for both entries, covering the finished floor, the subfloor, and the insulation.

Hi Robert! Concerning the gap between the end of my flooring and the rear doors - the issue is that at the very back, the corrugations stop about an inch shy of the doors, and knowing that I'd likely be resting a number of heavy items right on that spot as I moved them in or out of my rear garage area, I didn't want to risk the plywood chipping or breaking due to a lack of support directly underneath it. To add to this issue, the back also curves or bows outward in the middle, and so any support that you might try and add yourself (like I did at the sliding door entrance) would have to be a custom radius. In the end, since this area is going to be covered by a diamond plate cover anyway, it didn't feel like a worthwhile time investment to gain one inch of flooring in the garage area of my build. Hope all that made sense! Best of luck in your build!

@@ErikJohnson2020 OK- Got it. I never thought about heavy objects resting/ dropping/ clunking down on that spot. A lot of force would be concentrated there. And, as we are learning, these vans have some funky curves/ bends/ angles what have to be addressed. Thanks for the speedy response. Keep on putting these videos out for us : ). Looking forward to more of the build series.

Heyyyyy Erik!... we are going to be starting our floor install this week and in your video I didn't catch what screws you used. I would assume self taping metal screws but... Could you let me know please what ones you used. Kind and length. Much appreciated. Exciting times!.

@@Thedestressguy I used an exterior decking screw, self-tapping, with a torx-25 head, I think it was like 1-3/4" long. Might have been Deckmate brand, but I'm not certain. Good luck on your project!!

What do you recommend instead?

Yup! That's exactly what I'm planning to use. I thought about doing a roll-on like Lonseal, but the price and the hassle of the install seemed to outweigh the benefits.

@@ErikJohnson2020 I'm interested in your approach to this. When installing vinyl plank in a house they make a big deal about leaving a gap around the outside to accommodate thermal expansion and contraction, so the same must be even more true for a van where you'll see much more varying temperatures. I'm leaning towards letting my vinyl plank float on the floor, and anywhere a cabinet gets bolted to the plywood below, drilling a 1" (25mm) hole through the plank to let it expand and contract with the temperature variations. Your thoughts on this?

Hi Panda! The "expansion" gap around the perimeter of the vinyl plank flooring is also critical for you to install the planks properly, since you'll need a slight gap to fit the "pulling tool" in order to eliminate any slight gaps between the planks once you start laying them down. Thankfully though, this gap is super easy to cover up with some quarter-round trim or some other decorative trim. Combine that with toe-kicks on your cabinets, and I think you'll find the gap needed is hardly an issue. And from what I gathered of your description, it sounds like your plan is to install your cabinets on top of your plank flooring - which I wouldn't suggest doing, since the physical weight of the cabinets will prevent the planks from moving/expanding. I'd just install your cabinets directly on top of your water sealed plywood, and then anchoring your cabinets to your plywood is pretty straightforward. Honestly I'm not sure if vinyl planks really do expand/contract all that much. From what I've read, modern vinyl planks are quite stable relative to temperature based expansion, but regardless you're still gonna need that gap for a proper install. Hope that helps!

Correct - you don't want the screws to engage both the wood and the aluminum, otherwise the threads of the screw would have to perfectly sync with both materials as each screw exits the wood and then enters the metal. And since that's just about impossible to ensure, what will most likely happen is the threads of the screw will act like little ramps and end up lifting the wood away from the metal as the screw spins while trying to engage the metal.

@@ErikJohnson2020 Thank you-that makes perfect sense!! 🙏

It would, but that is why we only have non-foam materials touching the foam wherever possible, and in one spot where we had to have two foam boards touching, we used extra foam adhesive between the two pieces to prevent any squeaking (in addition to using foam adhesive on the underside for everything). Hope that helps!

@@ErikJohnson2020 I presume you’d know since the original post was a while ago. Thanks for sharing this, and the timely response with us. Brilliant!

Hi Shaun, I'm glad you found my channel too! 😊 As for why I didn't run the sheets sideways, plywood here in the states is most commonly in 4'x8' dimensions, and at 4' wide, you'd actually need 4 sheets to cover the length of the extended version of the Ford transit (165"). That and you'd have nearly 3' of "waste" from all four boards if you lay them in running sideways. w Whereas in my layout, I only used a total of 3 boards, and had very little waste. Hope that helps!