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 🙂
Thank you so much for all of this amazing information. We are just starting out build and the floor is on the immediate to do list.
We are going with 4-seasons and were wondering if you use the silicone between both the XPS and Floor and/or the XPS and the Mini-Cell (layer 1).
Thanks!
For floor I am thinking of using nice plywood with a liquid coating such as polyurethane instead of rolled vynil. (Polyurethane on wood is what we have in bowling alleys and roller skating rinks, so it seems it would be durable enough.) Any considerations? My thought is the floor in a van surface is very hard to replace or repair, while poly coated plywood can be repaired easily when I damage it.
Hello! We’re in the process of layout out the footprint of the floor and noticed you kept a gap between the ply/insulation and the rear doors. Is there a reason you did this instead of cutting holes for access to the spare tire etc? Hoping this settles a little squabble between us.
Thank you!
Some people extend their floor further back (but leaving access to the spare tire mechanism), so I’m pretty sure that’s not an issue!
I used 7 cans of 90 for the first 3 layers!!! Did I not need to glue some of these layers or did I apply too much?
1 – Minicell foam in floor ridges – 90
2 – Thinsulate – 90
3 – Minicell foam -90
Next up: 1″ XPS and 1/2″ baltic
Aloha,
I am considering a build with 3 versus 4 season flooring. What would you say the range of temps are for 3 seasons and also for the additional 4th season ( Canadian winter? )
Thank you for the time you invest in answering questions.
Hawaii summer to Colorado winter cannot be breached by van on roads but a barge carrying the van from the islands to the mainland….yes!
Hello! We have been following your flooring instructions and we are so grateful it exists! The amount of time and energy you put into this is just awesome. Thank you! I was wondering what type of bonding agent you used for the sheet vinyl? Did you opt for releasing or permanent? Thanks again!
Hi!
The adhesive we used is listed under “Material” section on this page. It’s this one: https://amzn.to/3fb9pBE
Hi, thank you for all the work and energy put into this website, lots of good informations!!!
I’m thinking to use expanded cork board for the floor insulation instead of xps or minicell.
I was wondering if there was any reason why you are not mentioning any natural materials for insulation (both floor and walls). Sure they have less R value, but does it makes such a big difference for such a small space? Considering the big pros for air quality and environment when using non-toxic materials, is it still much better to use conventional insulation?
What thickness minicell foam would you recommend for the subfloor?
Would this process work well for hardwood flooring too?
I’m a carpenter by trade, I would highly recommend staying away from hardwood in a van. There is too much variability in the environment… You’ll be traveling (presumably) between area’s of high (expansion) & low (shrinking) humidity levels, large temperature swings, not to mention the “in & out” nature of living in a van. Hardwood will likely be more expensive & is more susceptible to warping, buckling, and scratching. It’s your dream van, do what you’d like, this is the unfortunate reality of using real wood.
So, what would you recommend instead of birch plywood?
Thanks for this info. I am following your setup (one on the right). You recommend using Silicone to secure pink foam to the floor/minicell. Is it strong enough to bond the pink to the sections on floor and minicell?
Am I correct in understanding the the wood floor isn’t bolted down to anything? Is it just resting on top of the insulation? Does this pose any safety hazards? Or is it fine because it’ll have things secured on top of the floor and to the walls?
Love your site, thanks for your work putting it together!
Going with minicell per your recommendation. I’m curious your thoughts on butt joints on the plywood, especially with the possible give with the minicell under the plywood. I’m using 1/2” Baltic and trying to decide on doing biscuits or lap joint or something but wonder if you’ve considered this with the minicell route.
Thanks!
We didn’t use anything at the joint, but I think i would consider biscuit joint next time just to make sure… We’re not pros at woodworking, so maybe there are better solutions we’re not aware of?
Cheers
For sure join the plywood with some kind of joint. Minicell is spongey so the plywood will not stay level.
Dado maybe?
We went with the three season build per your analysis. I have a simple question in regards to Layer 1, Minicell installation between the corrugations. Is it absolutely essential to glue that layer to the floor? We’ve completed all our layers and installed as a fit test and the thought of taking everything back out is daunting. I can see the XPS material slipping and sliding but the Minicell seems to have less of that issue. We want to do things right and don’t want to cut corners. Thanks!
Some people do not use adhesive at all. That’s fine if you plan on adding permanent stuff on your floor after (cabinets, etc.).
Cheers!
I plan to combine your floor tutorial with electric radiant heating. Your explanations are concise & filled with rich informative making it possible to not only understand but make it customizable. Each step is broken down to small digestible mind nuggets. Kinda like thought legos.
Thank you!
Would sincerely appreciate a rundown of how you intend on doing that! I’m about to start on my 2019 Transit, and was considering radiant heating
Hi, what do you think of re-using the vinyl floor mat that comes with a transit cargo van as one of the layers in the floor build? For example, if using your 3-season, minicell only version above and placing the vinyl mat between the top layer of the minicell and the plywood, in order to provide a little extra insulation, without having to go the XPS route. What do you think?
Thank you for all the great info!
Angela
We didn’t get a vinyl floor with our Transit, so I’m not sure exactly how it looks so it’s hard to advise. But I’m not super keen on adding several extra layers; will it squeak? will it be well supported? Personally I think I would skip it. Is this for a winter (skiing) adventure van?
Thank you so much for the quick reply! Initially, I am thinking just 3 season, due to some health issues; but I would LOVE to take it out for a winter skiing trip eventually, so that’s why I was considering more insulation. I am currently living in it with no build whatsoever in the Arizona desert, so trying to do the floor under those circumstances is challenging, that’s why I was leaning away from the winter floor you laid out, because it seems a little harder to manage building that layout in my current circumstances. But if it really does make a big difference for warmth, I probably should do it. I just checked the underside of the black vinyl mat and it has a fabric or felt-like material on the bottom, so I guess that could be a problem, because it might be susceptible to mold. If you have any additional thoughts, I’m all ears! Thanks so much!
I’ve just learned about GPS foam insulation. It would seem to have a number of advantages over XPS (more stable, breathability, less moisture retention, compressive strength). Would you recommend it or am I missing some significant advantage to XPS? Any idea what adhesives would be used if it were substituted for XPS in your floor insulation plan?
At first glance, I don’t see a problem with it, except maybe its availability/price.
So you guys get any squeaking at all when driving ?
Not from the floor, but we get some from cabinets and walls…
Hi guys, thanks for the wealth of info. A couple of questions as I get ready to do my floor:
-You mentioned if you did it over again, you’d use minicell. Why that over XPS or ISO?
-Is the initial layer of minicell/XPS necessary, especially if we can’t find anything exactly .3″ (meaning things will remain uneven anyway)? Thinking about just starting with a layer of 1″ XPS/ISO
-For the subfloor, we can’t get baltic birch here…is any plywood okay, or should we stick with pressure treated at a minimum?
Thanks!
Hey Devon, did you end up foregoing the 0.30″ minicell filler for the corrugations? I’m thinking the same thing as you, wondering if XPS or GPS straight onto the van floor would work or if you’ve had issues with compression/cracking. Thanks!
I purchased minicell from the link they provided and got .3 and .25 that was listed as the Promaster sizes. I’m halfway through installation and so far it’s working well. I can update in a few days when I get it finished to let you know how it it turned out.
Do you feel like the floor is depressed when you step on it? I would prefer not to use any screws if possible but I feel like they would add a ”hard wood” feel when walking.
There’s no movement at all. All good!
what is the interior height after installing your snow chaser floor insulation system? Please let me know the distance from top of the second layer of vinyl flooring to the bottom of a ceiling rib. Thank you. I am so appreciative of your information and thoughtful analysis. Have a great day. Tim
76in is the clearance after installing the floor and the ceiling I believe. You can find all the dimensions in our interior layout pdf: https://faroutride.com/store/interior-layout/
antoine