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!
Disclosure: The method we propose below works for most people (including ourselves!), but some people are getting a few issues such as squeaking, bad adherence or uneven seam. The obvious and easy solution for 100% success would be to screw the floor to the van, but we decided to avoid this because of rust issues in the long term. So please make your own research (Google, YouTube) and choose the method that you’re the most comfortable with! 🙂
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.
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.
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):
6- Before adding the finish layer...
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):
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').
7.5- 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:
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 🙂
What are your thoughts on using a roll of closed cell foam carpet padding under the xps for 4 season insulation. Instead of cutting it to fit the voids, just let it mold to the floor and have one full layer. Something similar to the bed rug idea but still applying the 1” rigid foam on top of it. Thanks!
I’d be worried this would promote movements (and squeaks?). Personally I would skip the carpet!
salut a vous il y a t’il un inconvenient a mettre un xps plus épais que un pouces, 1 1/2 ou 2 pouces ?
merci a l’avance
Pas d’inconvénient à part la perte d’espace (minime)!
Curious if you used a stair nosing to finish the flooring where it butts into the existing van floor between the driver and passenger seats? If not, how did you finish this detail? Thanks for all the amazing free build info!! Just getting started in my build and already consider your website priceless.
We did use a stair nosing, but also had to “extend” it with wood because it was not long enough.
Two points to note for those following these instructions.
1. Corning now makes an NGX Foamular to replace the XPS. This new board has a lower environmental impact.
2. I have a 2019 Sprinter 144 and BedRug doesn’t offer the corrugated version for this van.
Seems like the the bedrug would be a good way to go to fill in the gaps and then cover it with Huber Zip-R-6 sheathing (water resistant barrier 1/2″ OSB with polyiso adhered to it, total thickness is 1.5″ and R value of 6.6 ). You could use the fitted van rug as a template to trip the Zip-R panels to fit. I would then use a biscuit jointer to connect the Zip panels.
Thank you for the thorough ride up and all the guides. I’m working on doing this in my econoline van now. Did you insulate the driver / cabin area for 4 seasons? Flooring goes right up to the back of the seats, but the front area is just carpet at the moment. Do you have any suggestions for up front?
We didn’t insulate the floor in the cabin, but added some Thinsulate in the door when we installed speakers (https://faroutride.com/speakers-upgrade/). We found Insulated Window Covers make a huge difference in the cabin.
Cheers, antoine
Hello! The guide doesn’t specify between using the Vanrug and the Vantred product from Bedrug. Which makes more sense to use for campervans? I’m planning to use that, then a layer of XPS, then vinyl:)
Hey there,
I am wondering if the 4 season floor in your van insulates so well that, when the weather is 0 degrees Celsius, you are able to wear socks in your van and not have cold feet, while not running any heater. In other words, in freezing temperatures, are you able to stand and walk around in the van with no shoes on while the heater is not running and not feel the cold coming through the floor. I ask because I have a height restriction, and I am wondering if I should insulate the floor less so I can stand up inside the van, as it may not matter since I will need to wear shoes inside anyways when the weather is cold. Any insight would be appreciated!
Hello from Montreal
In your new build, are you using a Bedrug Cargo Mat?
Just wondering how it holds against the weight of the cabinets pressing on the floor if you did.
Thanks
Hi!
Because we’re building a 4 season van (winter), we’ll most likely use thicker foam board. But using a plywood subfloor should distribute the weight over a larger surface of the bedrug and mitigate this.
Cheers,
Antoine
Noted above that you mentioned you would only treat the edges of the baltic birch plywood…but treat it with what? A sealant?
Any wood finishing such as varnish, Danish oil, etc. 🙂
Just putting this out here .
I went the bed rug method and did glue it to the metal floor itself because it has the corrugations. I did not glue my wood sheets to the bed rug as it won’t move or slide around after everything is sealed in. As I am not chasing snow I then laid my LVT flooring to the wood and silicone everything up and it seems to be holding up. Trial and Error with these vans.
Hey Tony,
I’m thinking about going this very route. What did you use to glue your bed rug to the metal floor? After having done this, any thought about using thinner plywood than 1/2? I already have to slump to stand up in my van, so every 1/4″ counts!
Thanks for any info you can pass along,
Will
Will I am sorry I am just barely seeing this. So with rug I glued it in using the 3M 90. It fits pretty well to the contours. I would probably put the rug in and cut a small section of plywood to set on it and then step on it and see how squishy or hard the floor feels with a less thicker ply. I hope this helps and is not too late.
Update us with your build
Hey Tony, (Ignore if my other comment shows up…)
What glue did you use to glue your bed rug to the floor? I’m planning on going the same route as you. Also, any thought on using thinner plywood than 1/2″? Think it would hold up with support from the bed rug? I already have to stoop in my van, so every 1/4″ counts!
Thanks for any info you can pass along,
Will
Thanks for sharing! We are planning to go this route as well – did you go with the Vantred or Vanrug option? I can’t really tell which one was suggested here.
This is one I used. BedRug VanTred | VTFT15L
Off of Amazon
Does foam add much sound insulation? I was thinking of using thinsulate instead.
Hey Guys!
I’m currently doing the flooring part of my build. I have a Transit EXT just like you.
I’m using a lot of your stuff to help guide me as I have NO idea what I’m doing!
I have purchased all of the Plywood and Foam Board I need and am about to start cutting it up to fit the van. Do you have any tips on sizing and cutting the materials for an exceptional fit with minimal wasted cuts?
I’m currently working on a file to have my foam & plywood CNC’d, that will be the most accurate 🙂
Otherwise: measure twice cut once 😉 The overall shape outline is rectangular, not much problem here. For the Pillar and wheel well, you can first create a template on a sheet of paper/cardboard, then when you’re happy with it transpose it on your plywood and cut.
Good luck, antoine
ABOUT BEDRUG — There are two types of Bedrugs:
1. VenTred (#VTFT15LE) made with PPO Plastic top and Closed Cell bottom – this is a more firm, smooth top, and is the flooring that typically comes stocked in Transits, only with with denim insulation on bottom (a real bummer for us Vanlifers!)
2. VanRug (#VRFT15LE) made with Polypropylene top and Closed Cell bottom – VanRug is softer, intended to be used like a cushiony, waterproof, plastic “outdoor carpet”
We have decided to purchase the VanTred, as we want a firmer top to support the 4 season “Snow Chasing” layering version suggested above — in this order:
1. VanTred Bedrug Floor Liner
2. 150 Foamular (1.5”) Pink Foam Board (only because we can’t get 200 in 1.5”)
3. 1/2 or 3/4” Marine Plywood
4. Sheet Vinyl
So here is my question. We plan to do a typical camper-style conversion with sliding platform bed, garage for bikes (and maybe a second bed) with hidden shower and built in kitchen upper and lower cabinets…. I’m curious what you folks recommend — Should we let the layers all be free flowing, or should we adhere them together as follows:
A) The PPO plastic top Bedrug to the Foamular board? Or maybe,
B) The foam to the plywood subfloor (to which the vinyl be adhered on top)? Or
C) Adhere all layers with spray foam to close gaps on the sides? And….
D) What type of adhesive would you suggest for these different substrates?
This is our first van build, and I truly appreciate your feedback!
🙂 Jim & Jill Marie
Hi Jill
I am just reading this now, and your layer plan is what I am thinking of doing. you are a couple months ahead of me. What did you decide to do, and how did it work out?
thanks
Kris
When you lay the XPS boards, do you glue them to each other or are they just put next to each other?
Good question, it’s been a while and I don’t remember exactly what we did… I think I’d add some adhesive, just to help prevent squeaks!
I am getting ready to put a floor in a sprinter van 2022. I am struggling to see the value of putting insulation between the ribs of the floor. The EPS in 1 inch with a half inch plywood seems more than enough to handle the weight of humans and anything else placed on it. Am I missing something?
You are correct, the insulation between the ribs is to add more insulation values, not to add support for weight.
Some people skip the insulation between the ribs, but we decided to go with it!
Cheers,antoine
I noticed in this it wasn’t specified how you would ‘attach’ the bedrug/vanrug to plywood if you went that alternate route instead. Would you need to adhere the two layers at all? Or would you need to use something like epoxy to bond the two.
I have the same question, only I prefer NOT to use Adhesives between the VanTred (PPO plastic top with closed cell padding) bedrug and the plywood, because the bedrug looks so nice I’d hate to ruin it! So I’m wondering if it will squeak or shift without Adhesive? And what about maybe putting a thin layer of closed cell or TAI Thinsulate (or suggest ?) between the two for added insulation and grip? Anyone know??
Same question re: bed liner, but I’m about to find out! Our floor can’t be fixed in place immediately as we need to rout out some of it for a shower pan, so we’ll have some time using it where everything’s been cut to fit but there’s no glue on the layers. We’ll see how it goes! I will check back in, but it’ll be some time.
Just lay plywood down no adhesive. It’s heavy enough it won’t go anywhere especially if you’re installing other sinks, showers etc. on it.
I purchased a bedrug liner! I have a similar question, only I prefer NOT to use Adhesives between the VanTred (PPO plastic top with closed cell padding) bedrug and the plywood, because the bedrug looks so nice I’d hate to ruin it! So I’m wondering if it will squeak or shift without Adhesive? And what about maybe putting a thin layer of closed cell or TAI Thinsulate (or suggest ?) between the two for added insulation and grip? Anyone know??
Is “Polyisocyanurate Rigid Foam Insulation Board” a better option over the XPS? The Polyiso has a higher r-value and 16-20 psi load-bearing. I would appreciate your thoughts on this.
Thanks.