And now is the time to install a floor in our van conversion! A floor has many other critical functions than just supporting our feet. Indeed, a proper floor installation prevents water infiltration (= rust), provides thermal and noise insulation, and serves as an anchor for the cabinets. In addition, it should be resistant to wear, be able to withstand enough weight, not produce any squeak, and … look good (yep, that counts!). There are many ways to install a floor in a van, but keep reading to learn our take on it!
The information in this article is still relevant. But we are currently building our second van, and you’ll find our latest and greatest work here:
Disclosure: This post contains affiliate links, which means that if you click a product link and buy anything from the merchant (Amazon, eBay, etc.) we will receive a commission fee. The price you pay remains the same, affiliate link or not.
Material: 3 Seasons
Good for occasional sub-freezing temperatures.
| LAYER | ITEM | QUANTITY | LINK |
| 1 & 2 | Minicell Foam | 7 sheets | eBay |
| 3 | Preferred: Baltic Birch Plywood (½”, 4’x8′) | 3 sheets | Cheaper to source locally |
| Alternative: Exterior Plywood (¾”, 4’x8′) | |||
| 4 | Vinyl Floor | 13′ wide x 8′ long | Cheaper to source locally |
| 0/1 | 3M 90 Spray Adhesive | 1 | Amazon |
| 3/4 | Vinyl Floor Adhesive | 1 | Amazon |
| Wood Filler (only if using exterior plywood) | 1 | Amazon | |
| Silicone II (for caulking the vinyl floor periphery, step 7.6) | 1 | Amazon | |
| Great Stuff “Gaps & Cracks” | 1 | Amazon | |
| Vinyl Floor Seam Sealer | 1 | Amazon | |
| Stair Edging (1-1/8″) | 1 | Amazon |
Material: Snow Chasing
1" thick XPS for Full-On Snow Chasing!
| LAYER | ITEM | QUANTITY | LINK |
| 1 | Minicell foam | 3 sheets | eBay |
| 2 | XPS foam (1″ thick, 4’x8′) | 3 sheets | Cheaper to buy locally (product example: Insulation4us) |
| 3 | Preferred: Baltic Birch Plywood (½”, 4’x8′) | 3 sheets | Cheaper to source locally |
| Alternative: Exterior Plywood (¾”, 4’x8′) | |||
| 4 | Vinyl floor | 13′ wide x 8′ long | Cheaper to source locally |
| 0/1 | 3M 90 Spray Adhesive | 1 | Amazon |
| 1/2 | Silicone II | 3 | Amazon |
| 2/3 | PL300 Foam Board Adhesive | 2 | Amazon |
| 3/4 | Vinyl Floor Adhesive | 1 | Amazon |
| Wood Filler (only if using exterior plywood) | 1 | Amazon | |
| Great Stuff “Gaps & Cracks” | 1 | Amazon | |
| Vinyl Floor Seam Sealer | 1 | Amazon | |
| Stair Edging (1-1/8″) | 1 | Amazon |
NOTES:
- Minicell thickness: Transit = 0.40″, Sprinter & ProMaster = 0.30″. Choose thickness in eBay store.
- Quantities shown are for our van (Transit extended-length) and may vary according to your van model. For Minicell quantities, follow recommendations in product description (eBay store).
- We used ½” XPS (in pink) to fill the corrugations, but we would use Minicell if we had to start over. Read our “Second Thoughts” at the bottom of this page for more info!
Tools
| Item | Description | Quantity | Link |
| Snap-Off Utility Knife | Stanley 18mm. | 1 | Amazon |
| Caulking Gun | For 10 oz cartridge. | 1 | Amazon |
| Jig Saw | DEWALT Cordless Lithium-ion 20V. | 1 | Amazon |
| Blade Set for Jig Saw | 14 Pieces. | 1 | Amazon |
| Circular Saw | DEWALT Cordless Lithium-ion 20V, 7¼ with brake. | 1 | Amazon |
| Circular Saw Blade | DEWALT Precision Finish Blade 60 tooth. | 1 | Amazon |
| Trowel | 1/16″ x 1/16″ x 1/16″ Square Notch. | 1 | Amazon |
| Rolling Pin | To roll tasty vinyl pies. | 1 | Amazon |
| Painters Tape | To protect the van walls when working with Great Stuff Foam. | 1 | Amazon |
Good To Know
Floor Layers In A Nutshell
Layer 1: To Fill corrugations
- Provides thermal insulation (and sound insulation to a certain extent).
Layer 2: Top of corrugations
- Provides thermal insulation (and sound insulation to a certain extent).
Layer 3: Underlayment
- Provides a smooth and level surface for good adhesion of the finish layer.
- Supports and distributes weight.
- Serves as an anchor for cabinets.
Layer 4: Finish
- Looking good!
- Protects against liquid infiltration (and therefore, rust). Trust us, spills WILL happen! That’s why we went for large vinyl sheets (2), instead of multiple vinyl tiles (to minimize seams).
- Shall be wear resistant.
Choosing A Plywood
Baltic Birch
The plywood underlayment shall be moisture resistant, exempt of any warp, and the surface common with vinyl flooring shall be nice and smooth. That’s why we prefer Baltic Birch. It is laminated with exterior grade adhesive, it’s straight, the surfaces are smooth (no wood filler needed) and it’s very dense (screws grip better in it). As a result, ½” should work well. Note that we wouldn’t treat the entire plywood sheet: just the edges. Indeed, it is sandwiched between the vinyl floor and the foam (XPS or Minicell), so it’s not exposed to high level of moisture or condensation.
Exterior Plywood
Exterior plywood commonly found in hardware stores is glued using exterior grade adhesive and some of it is also treated for protection against fungal decay, rot, and termites. Compared to Baltic birch, it is made of thicker plies, so fewer plies are needed to obtain the same thickness. Therefore, the resulting plywood is less dense and warps more easily. We’ll go ahead and say that even if the underlayment is exposed to some moisture, it’s not a requirement to use treated plywood because it is “protected” by the vinyl floor and the foam (XPS or Minicell). If using plywood to fill the corrugations, that’s another story…
Choosing the XPS foam
You’ll find XPS branded as “Foamular” 150, 200, and 250. This number is relative to its compressive strength. 150 is capable of supporting 15 PSI, 200 can support 20 PSI and 250 is capable of 25 PSI. Knowing that a human footprint is equal to approximately 16 PSI, it’s a good idea to choose XPS higher than 150 (15 PSI). Note that the plywood underlayment will take care of distributing the weight to a larger surface, so any foam should be OK. That being said, there’s a pretty good chance you walk on the foam during the van build (before installing the underlayment); you’ll appreciate if the foam doesn’t collapse under you 🙂
Attaching The Floor
Believe it or not, there’s no need to secure anything; the floor isn’t going anywhere! The large plywood sheets, combined with the weight of the cabinets (and others) will ensure the floor stays where it belongs. Doubt it? We completed our conversion in 2017 and our floor hasn’t moved at all. And many people have used this technique with the same results.
So, why are we recommending to use adhesive anyway? The adhesive doesn’t provide any kind of “structural” bond: its role is to keep everything where it belongs during the floor assembly & to prevent squeaks, especially with XPS. We repeat, XPS squeaks if not attached properly! Keep reading for recommended adhesives.
All of that being said, we see a scenario where we would attach the floor to the van: if no cabinets are added to the van and a slide-out-bike-rack is installed. Then, it might be a good idea to attach it (because of the long lever when the bike rack is out).
Adhesive Compatibility
| Minicell | XPS | Metal | Wood | |
| 3M 90 | Yes | NO! | Yes | Yes |
| 3M 78 | Yes | Yes | Yes | Yes |
| 3M 77 | Yes | Maybe | Yes | Yes |
| Great Stuff (Gaps & Cracks) | Yes | Yes | Yes | Yes |
| Silicone II | Yes | Yes | Yes | Yes |
| PL 300 | No | Yes | Weak | Yes |
Choosing the right adhesive
Like it or not, there’s no perfect “universal” adhesive (because CHEMISTRY). The “best” adhesive depends on materials, application context, use context, availability, and cost. Based on the previous table, here are some options:
- 3M 90: This is the stuff we used to glue Thinsulate to the walls and ceiling. Works great, except it WILL attack XPS. Bond time = 15 minutes.
- 3M 78: Designed specifically for foam, it’s probably the best option (technically speaking). However, it’s costly and more difficult to find. Bond time = 30 minutes (it means you have 30 minutes to put everything together and apply pressure).
- 3M 77: It used to be safe for XPS (polystyrene), but 3M had to change the ingredients recently. We’d recommend testing it before using it with XPS. Bond time = 15 to 30 minutes.
- Great Stuff Gaps & Cracks: Not technically an adhesive, but people use it successfully to glue foam. It’s very cheap and easy to find, but it can be messy if not careful. Bond time = less than 10 minutes? (test it, not sure exactly).
- Silicone II (not acrylic): Not technically an adhesive, but it works great for the current application (prevent squeaks). Quite cheap and easy to find. Bond time approximately 15 minutes.
- PL 300: That’s what we recommend for bonding XPS to wood. Won’t work on metal or with Minicell. Bond time = 20 minutes.
Joining the plywood (to get an even seam)
Some people are getting uneven seams where the plywood joins together. We personally didn’t get this issue, but we would highly recommend looking into joining techniques to increase your chances of success, such as:
Lap Joint
Biscuit Joint
Some don'ts
Framing
We often see people framing their floor, the justification being that it “stabilizes” the floor. Unless you are using compressible insulation (Thinsulate, wool), there’s just no need to do this. The van’s floor is stable enough. Good reasons not to do it: 1- frames are thick and vertical space in a van is precious. 2- Wood is a good heat conductor, so the frames create thermal bridges (in other words, it’s bad for insulation. Check out our “Insulation Guide” for more.).
Metal screws
Each screw added to the metal of your van is a potential ignition point for rust. Knowing that the floor is a very sensitive zone for rust, we really recommend not screwing liberally through it. There can be some exceptions to this (we personally drilled a few holes for the Webasto & Propex heaters, composting toilet exhaust, grey water drain, propane locker vent and floor vent), but the bare metal of each added hole/cutout should be primed + painted to prevent corrosion.
Saving Time and Hassle
We recently stumbled on the Bedrug Cargo Mat. It’s a 1/2″ thick closed cell foam mat (polypropylene = resistant to chemicals & weight) that is custom-made for various vans (Transit, Sprinter, ProMaster, etc.) & wheelbases (short, long, extended). The mat fills the corrugations (neat!), the custom fit means there is no trimming involved (which can literally saves you HOURS!), and as a bonus the mat can be used as a floor template (for the plywood or else). We think it would make a great alternative for the minicell insulation in the “3 seasons” floor layout (layers 1 & 2), or it could be used as a standalone floor for simpler builds.
(choose your van & model from the search result)
And now let's get to work!
1- Clean Everything:
Cleaning is NO FUN.
2- Fill the corrugations with the Minicell (Floor Layer 1):
NOTE: We used ½" XPS for this step (as shown in the pictures), which is too thick, so we would use Minicell if we had to start over.
2.1- Cut the XPS (Minicell) using the utility knife.
2.2- Install on the van floor using adhesive (3M 90 adhesive with Minicell).
The XPS Shake:
Put some of the leftover C-200 XPS strips in the blender with vanilla, protein powder, ice cubes, and decorate with mint. Enjoy!
3- Install the XPS or Minicell (Floor Layer 2):
3 Seasons = 0.25" thick Minicell.
4 Seasons = 1" thick XPS.
3.1- Isabelle crafted a template from some random brown left overs. It helped making clean cuts on the insulation.
2.2- Add the XPS or Minicell and secure in place using the adequate adhesive (XPS = Silicone II, Minicell = NONE).
We left a gap of about ½” all around the van wall to account for installation variations and to ensure there would be no squeaking noise. This gap will be filled later with Great Stuff.
4- Install the plywood underlayment (Floor Layer 3):
TIP: Use the foam (from layer 2) as a template, it'll save you some time! And don't forget to take your shirt off when using a circular saw.
Isabelle approves the result and the shirtless display.
Secure the plywood to the XPS using PL300 (remember, this is to prevent squeaks) and apply weight. If using Minicell, no adhesive is required (Minicell doesn't squeak).
Cannot find any weight? Leaving a bowl of food on top of the surface to be glued will inevitably attract heavy weight.
6- Before adding the finish layer...
Cavities on the plywood were filled with wood filler and then sanded flush. If using baltic birch, this step is not required as it is already smooth.
To seal the gap and make a nice & flat surface for the vinyl floor, we overfilled the gap with Great Stuff (Gap & Cracks), let it dry, and then trimmed it flush with the plywood sheet (using a utility knife).
7- Install the vinyl sheet (Floor Layer 4):
7.1- We bought a sheet of 8'x13' vinyl and trimmed it as follows:
The goal is to have the "planks" oriented lengthwise and to have the seam "hidden" under the bed:
7.2- Something like this:
TIP: We were told not to trim the vinyl to its final dimensions right from the start, and that was a GOOD TIP! Work with extra length, and do the final trim AFTER it's glued. Indeed, it’s almost impossible for the vinyl to return to the same exact location after the glue is applied (because it will slightly move and stretch). That's why we initially trimmed the vinyl to 6.5', which is slightly larger than its final dimension (~6').
7.3- Follow the instructions on the vinyl floor adhesive: use the appropriate trowel and the right amount of adhesive (not more).
7.4- The vinyl was stretched and bubbles removed using a rolling pin. Notice the extra material around the periphery: that will be trimmed to its final dimensions later.
7.5- Then we proceeded with the second vinyl sheet. To make a nice seam between the two sheets, we slightly overlapped them and trimmed both sheets (simultaneously) so they have the same exact trim. No picture of the seam, sorry 🙁
7.6- We caulked the vinyl floor periphery with GE Silicone II. Unlike acrylic, Silicone is permanent: it doesn't dry and doesn't crack, it's very flexible and it remains elastic from -55F to 400F.
8- Install stair edging:
As a final touch, we added an aluminum stair edging at the sliding door, passenger/driver seats, and at the back of the van (garage).
Because the stair edging is only 1-1/8″ and our floor is thicker (we went for the "snow chasing" mode!), we added a wood trim that we painted grey to match the van's magnetic grey. The wood trim is screwed into the plywood layer of the floor (the screws are hidden by the aluminum edging).
9- OMG WE HAVE A FLOOR!
On Second Thought...
Things we would do differently
- We initially went for ½” XPS to fill the corrugations and we would now go for Minicell (because it has exactly the right thickness).
- We initially installed a layer of MLV (mass loaded vinyl) for soundproofing, but we feel it was superfluous. This thing is HEAVY and sandwiching it among the floor layers is not how it’s meant to be installed to be effective. So save yourself the trouble!
- We used exterior plywood and left it in the sun for some time… It warped the plywood big time. Next time we’ll use Baltic birch and keep it away from the sun!
- This page was updated to reflect how we would do things next time!
How cold is the floor in winter?
Heat rises, right? So we expected our floor to be constantly cold. Turns out the Webasto placement is perfect as it blows hot air parallel to the floor. As a result, our floor is nice and warm even when it’s way below freezing temperatures outside. Neat!
That being said, it might not be the case for different layouts… If your “living area” is in the back and your Webasto in the front, the floor might be cold in your living area.
Any change over time?
Nope! The floor is still level and doesn’t squeak 🙂
How about …
BedRug
Temptrol (a foil cloth)
Minicell
Temptrol (the Minicell acts as the dead airspace needed with radiant barriers)
Birch plywood
Finish floor
Aluminum angle to finish the edges at the side and rear doors
Love your page, answered many questions for my upcoming build. Thanks!
Floor insulation is a must. It’s not just because of the cold, but because of the heat.
I was driving on I-70 in north of Moab in the summer pre-pandemic and the floor was hot. No wonder the dogs were piled up on the passenger seat.
Floor insulation is a must for any season. Especially the ways things are heading for our abused planet.
After watching videos of so many builders drive themselves nuts trying to cut/fit/trim/etc. floor layers to wall contours, I’m stoked to have just now picked up the BedRug cargo mat you mentioned for my EWB Transit build. Got it for $150 from Amazon, sold as “new with packaging damaged” by their warehouse…i.e., returned unused and undamaged by a customer because of the shipping condition, but certified by Amazon with a thirty-day return guarantee.
To echo some things you said: I mean, yeah, it’s another $150 added to the build, but assuming it works out, there are cost offsets: a different underlayment, cardboard (because I can use the mat as a template), adhesive, etc. And of course there’s the time…Instead of spending hours and hours and hours on templating, I can just lay this thing down over the foam and plywood and sheet vinyl (with some extra edge length for trimming) and trace around it and boom! Ready for installation.
I intend to let the foam and subflooring float over it. I’m thinking the friction of the mat oughtta hold the foam in place.
Disclaimer: all theoretical but conceptually sound. I’ll report back.
We’ve just received ours too! Looking forward to install it and see how it fits!
Hi Isabelle, looking to start on floor. How did you like the Bed Rug and what did you install on top of if ?
Thanks,
Andy
How did you install on top of your bedrug??
I just received mine and am now trying to decide on plywood thickness and if I want to do click in place vinyl planks or just vinyl sheeting on top of that.
How has it worked out Ed? Thinking of doing the same thing
Ed et al.
Is there any significant VOC off-gassing of the Bedrug Cargo Mat. If yes, how bad and how long does it smell? I would like to use it, but due to very sensitive lungs, this is an important concern.
Thanks,
Ed
I lay down mine second week of July, off gassing would be a big word. It did smell a bit for a week or two. Currently absoloutely no smell what so ever.
I just got the BedRug VanTred and laid it out. It does not smell at all to me, and I tend to notice things like that. The new van has far more smell than the VanTred.
does the mat come ribbed on the bottom to fit in the floor treads? if not, is that a problem?
Hi Shebird, yes it’s ribbed to fit, as long as you get the correct size 🙂
I forgot to mention that I ordered Esplori Trim pieces for my floors front, back, and sliding door openings. $300…but it turned out NICE. I started to attempt to cut Oak Finished boards to trip it out, but the way you buy oak ran into $50 just for the rear opening and I still had to glue two pieces together and rip it to dimension to fit…not to mention design it, and sand and finish it. Esplori saved me a lot of time and it is 1st Class…so the total cost of what I did is in the +$900 range. The Esplori does require a bit of trim to fit up perfect but the give you a length that is close to whatever you come up with for your final dimensions; I simply used my hacksaw, bench grinder, and a file to fit it perfect.
https://esplori.com/products/floor-trim?variant=37569534656679
I’m just beginning my build. I just finished putting vinyl covering onto the plywood. NOTE: Have you considered using 3/4″ Tongue and Groove Plywood? To router a Lap Joint, or use biscuts might work…but “T&G” will provide a more secure and a tighter, and more flush fit. 3/4″ T & G is designed for 24″ on Center spans…for flooring. Meaning: It will stand up to whatever you throw at it. Will Biscuts? Seven 0 Savage on youtube routered lapjoints and it came apart on him. So then he did it all over with biscuts…Did it work? Hard to tell.. Well, I just finished mine…as far as I can tell, I’m the only one that has used T & G and I can say for sure, I had none of the other problems people talk about on youtube etc…I am very happy with it. It is solid, and the vinyl cover required zero extra work to bring the T & G seams together for a nice even, flush smooth fit. I can jump up and down on it and it is SOLID…Just a thought…thanks for all the work you’ve put it here.
Thanks! We never heard of T&G plywood. We’ll look into it and update the page 🙂
T&G Tends to warp much more with the changes of temperature and vibrations, so sheet vinyl, though there are fewer options, is much better for the campervan environment.
Hi Guys, having trouble finding XPS 250. Would you use the 150 ????
Live in Reno/Tahoe area.
Thanks for any advice and for such a fantastic informative site.
Yes that would work, since the plywood will distribute the weight over a larger surface!
Is it easier to cut to fit. Then trim the half inch off the side after? (Trimming the 1/2” before glue)
We only did one cut, as our template already included the gap. I don’t see any gain to do a two-step cut.
I just started making floor templates using 7″ wide strips of cardboard rough fitted around, then scribe with a pen and 1/4″ fender washer. This will give you a 1/2″ offset to the inside.
Cheers!
Did you join the plywood together before or after placing it in the van? I imagine it would be a big job to carry the whole thing in as one peice, but if I try and join it with biscuits while in the van, how do I compress the joints together to let cure? Also, when would I paint it? As indovidual sheets or once it’s all biscuit jointed together?
Also, where in this order of operations would you put the pl300 down?
Home Depot was selling sound proofing boards- fairly reasonable- I cut those boards up to fill in the flooring gaps. The material was a little friable, so I taped the edges. It has worked really well in my Ford 250 Transit. I covered it with 1/2 inch insulation and then plywood and sheet vinyl.
We are having a hard time finding XPS in California, there’s some kind of regulation against it. Are there any alternatives we can look into?
Should 1/2 Baltic Birch plywood subfloor be primed with anything or left bare. I did notice that the installation instructions for using the vinyl adhesive says plywood should be free of oil-based sealer.
Hi Antoine and Isabelle,
I am starting a conversion on a 2007 sprinter. Your guides have been very helpful!
The floor of my van has several screw holes and rivnuts from the previous owner. I am considering leaving the holes open to act as weep holes and leave an air gap in the corrugations.
What are your thoughts on that? Would this help or hurt the condensation and insulation of the van?
Hi! Where did you find the large vinyl sheets? I am from Mtl and all I can find are vinyl planks… I wish I knew where to go
We bought it in Laval, here exactly: https://goo.gl/maps/9XKHwPvBgsxRQ7C9A
But that was like 4 years ago…
Good luck!
I would love to do a similar flooring system for my van; but I plan to use my van to transport motorcycles. Do you feel the XPS will hold up with that kind of compression? Thank you! Truly appreciate your blog!
If you add plywood sheets on top of it, it will!
Cheers 🙂
I used the silicone to adhere the XPS to the minicell//van floor following the instructions outlined in your guide and the product description linked on this page, but several corner areas are now coming up and did not adhere at all. I had weights laid on top of the floor for a little over a week to make sure the process of adhesion was tight. Should I worry about this? If so do you have any suggestions? I am now at the process of doing the gaps n’ cracks but am worried about some of the areas that did not adhere well.
My husband and I are TOTALLY loving this site and are reading and re-reading everything you have written. We are preparing to start the flooring on our Ford E350 (woo hoo!) For filling in the metal indents/grooves we are very interested in the Minicell. XPS under 1″ thickness is impossible to locate these days. Can you tell us whether Minicell absorbs water (kind of like a sponge)? Thanks a million for what is probably the most comprehensive and easy-to-follow site EVER!
Minicell is closed cell foam, so it does not absorb or retain water! We would never recommend it if that was the case 😉
Thanks for the kind words, good luck!
antoine
Can I install another type of flooring (vinyl planks, for example) over the top of the plywood? Do I need to do anything differently with the rest of the flooring in that case?
I have friends who have done this with both vinyl planks and wood planks. They say the planks always separate, I’m guessing because the expanding and contracting plywood underneath.
I have .40″ minicell down in the corrugated valleys of the floor. As I am putting in a 4-season floor, my next layer will be 1″ XPS foam. Your recommendation is to use Silicon II as an adhesive of sorts but primarily to prevent squeaking. My question is where to put the Silicon II. Am I to lay a bead of silicon on every metal rib? Or on every metal rib and also on each minicell “rib”? That would seem to require a LOT of silicon, just checking. Also wondering if the dry time of the silicon is a concern, and If the foam needs to be weighted after being put down. Thinking thru the process, I am guessing it will be advantageous to cut the plywood at the same time and to put the plywood down on the XPS (without using the PL 300), just so that weights could be placed on the XPS. your comments appreciated!!!!
I’m approaching the same step, Tim. Assuming you are past this now, what did you do? Any thoughts?
Guys you wrote ‘Wood is a good heat conductor’ – this is totally false and undermines all of the rest of this text. If I am wrong please show me a source.
Cheers!
It’s all relative I guess. Metal is definitely a better heat conductor than wood. But wood is a better heat conductor than insulation material.
For example, in houses, the wood studs can create thermal bridges: https://www.progressivefoam.com/thermal-bridging-and-how-to-stop-it/
Cheers,
antoine
Thank you. Any info on how L track might be inserted into the floor?
Thanks. Chris