Floor Installation in a Camper Van Conversion

Van Conversion Floor

Floor Installation in a Camper Van Conversion

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 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!

Last Update: January 2020

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Portrait

Time Spent

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Total Cost

$ 0 USD

Material: 3 Seasons

Good for occasional sub-freezing temperatures.
LAYERITEMQUANTITYLINK
1 & 2Minicell Foam7 sheets eBay
3Preferred: Baltic Birch Plywood (½”, 4’x8′)3 sheetsCheaper to source locally
Alternative: Exterior Plywood (¾”, 4’x8′)
4Vinyl Floor13′ wide x 8′ longCheaper to source locally
0/13M 90 Spray Adhesive1Amazon
3/4Vinyl Floor Adhesive1Amazon
 Wood Filler (only if using exterior plywood)1Amazon
 Silicone II (for caulking the vinyl floor periphery, step 7.6)1Amazon
 Great Stuff “Gaps & Cracks”1Amazon
 Vinyl Floor Seam Sealer1Amazon
 Stair Edging (1-1/8″)1Amazon

Material: Snow Chasing

1" thick XPS for Full-On Snow Chasing!
LAYERITEMQUANTITYLINK
1Minicell foam3 sheets eBay
2
XPS foam (1″ thick, 4’x8′)3 sheetsCheaper to buy locally (product example: Insulation4us)
3Preferred: Baltic Birch Plywood (½”, 4’x8′)3 sheetsCheaper to source locally
Alternative: Exterior Plywood (¾”, 4’x8′)
4Vinyl floor13′ wide x 8′ longCheaper to source locally
0/13M 90 Spray Adhesive1Amazon
1/2Silicone II3Amazon
2/3PL300 Foam Board Adhesive2Amazon
3/4Vinyl Floor Adhesive1Amazon
 Wood Filler (only if using exterior plywood)1Amazon
 Great Stuff “Gaps & Cracks”1Amazon
 Vinyl Floor Seam Sealer1Amazon
 Stair Edging (1-1/8″)1Amazon

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 varies according with 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

ItemDescriptionQuantityLink
Snap-Off Utility KnifeStanley 18mm.1Amazon
Caulking GunFor 10 oz cartridge.1Amazon
Jig SawDEWALT Cordless Lithium-ion 20V.1Amazon
Blade Set for Jig Saw14 Pieces.1Amazon
Circular SawDEWALT Cordless Lithium-ion 20V, 7¼ with brake.1 Amazon
Circular Saw BladeDEWALT Precision Finish Blade 60 tooth.1Amazon
Trowel1/16″ x 1/16″ x 1/16″ Square Notch.1Amazon
Rolling PinTo roll tasty vinyl pies.1Amazon
Painters TapeTo protect the van walls when working with Great Stuff Foam.1Amazon

Good To Know

Floor Layers In A Nutshell

Layer 1: To Fill corrugations

  • Provides thermal insulation (and sound insulation to a certain extent).
  • Increases support surface for LAYER 2.

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 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 are glued using exterior grade adhesive and some of them are also treated for protection against fungal decay, rot and termites. Compared to Baltic birch, it is made of thicker plies so less plies are needed to obtain the same thickness. Therefore, the resulting plywood is less dense and warp more easily. We’ll go ahead and say that, even if the underlayment is exposed to some moisture, it’s not required to used treated plywood as 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 relate 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 equals 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 does’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 move at all. And many people have use 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

 MinicellXPSMetalWood
3M 90YesNO!YesYes
3M 78YesYesYesYes
3M 77YesMaybeYesYes
Great Stuff (Gaps & Cracks)YesYesYesYes
Silicone IIYesYesYesYes
PL 300NoYesWeakYes

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. Base on the previous table, here are some options:

  1. 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.
  2. 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).
  3. 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.
  4. 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)
  5. 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.
  6. PL 300: That’s what we recommend for bonding XPS to wood. Won’t work on metal or with Minicell. Bond time = 20 minutes.

Some don'ts

Framing

We often see people framing their floor, the justification being that it “stabilizes” the floor. Unless if 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.

And now let's get to work!

1- Clean Everything:

Cleaning is NO FUN.

Clean your mess

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 smoothed.

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 trim it flush with plywood sheet (using an utility knife).

Van Conversion Great Stuff Overfilled Flushed

7- Install the vinyl sheet (Floor Layer 4):

7.1- We bought a sheet of 8'x13' vinyl and trimmed it as follows:

Vinyl-Sheet-Trim-Van-Conversion-(Before)
Before.

The goal is to have the "planks" oriented lengthwise and to have the seam "hidden" under the bed:

After.

7.2- Something like this:

TIP: We were told not to trim the vinyl to it's 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 that the vinyl will 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 🙁

Floor Installation Camper Van Conversion (4)

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.

Floor Installation Camper Van Conversion (Silicone)

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 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!

Floor-and-banana

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 install 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 rise, 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 squeaks 🙂

STAY IN TOUCH!

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about us

Nice To Meet You.

Hello! We’re Isabelle and Antoine 🙂 In 2017 we sold our house (and everything in it), quit our engineering careers and moved into our self built campervan. We’ve been on the road since then and every day is an opportunity for a new adventure; we’re chasing our dreams and hopefully it inspires others to do the same!

199 thoughts on “Floor Installation in a Camper Van Conversion”

    • Our “3 seasons” layout use the same type (minicell).
      Our “Snow chasing” layout use XPS on top of the corrugation, because it’s easy to procure 1″ thick XPS (or similar) from the hardware store.

      Reply
  1. Hey gang!
    I see you did not secure the floor to anything and I completely understand why (the weight of cabinets, etc). I’m planning on building your bike pull out drawer with a platform bed over top and that’s it (just working with a Ford transit connect). How do you recommend I secure the floor to the vehicle so the weight of the door is secured at full retraction?

    Reply
  2. Hello! I followed your approach on my 2020 Sprinter build-out (thanks for your work documenting!). I have a seam where two sheets of plywood come together, approximately lined up with the rear of the sliding door opening. I have reviewed lots of other van builds and they have many ways of dealing with this seam to ensure it is always level. Some use wood biscuits to join (probably not going to work on 1/2 inch plywood), another option is to replace a couple of the foam insulation strips with plywood glued onto the metal of the van, and then screw the baltic birch layer to those strips. I see in some of your pictures that these two pieces of plywood are not perfectly level. My question for you: how did you ensure these are perfectly level prior to installing the vinyl and have you noticed any issues with this seam as you’ve been living in the van since the floor was installed? Thanks!! Russ

    Reply
    • Hi we started out with a slight see-saw action on our plywood build out, but put a liberal amount of epoxy down the cracks between pieces. We used a metal scraper to insure a level top surface. Now the plywood is as one with nary a creak or bow to be found. Stinky work but well worth it!
      Good luck, Pat

      Reply
  3. hi Antoine-we are getting close to ordering a 2021 transit crew van-we have the option of ordering the heavy duty vinyl flooring (7/16″ thick) with scuff plate on the back and step area of sliding door. If we have the vinyl flooring, I’m thinking we can skip the foam insulation and just lay down plywood over the vinyl flooring? do you think that’s reasonable? if so, would you glue plywood to the vinyl? we’re in colorado at 6K feet and plan to camp etc up to 11K or so.

    Reply
    • I would take out your insulation underneath and redo. I believe it is recycled denim which will hold moisture. I have a 2020 that I’m trying to figure out!

      Reply
  4. Looks like XPS may no longer be available in California, among a bunch of other states as well as Canada. Looks like regulatory changes are requiring stricter emissions standards.

    NGX appears to be what is replacing it, by the same company, but it is not widely available just yet. Home Depot still carries the small 2’x2’x1″ panels, but the SKUs for the larger panels are out of their system.

    https://www.roofingcontractor.com/articles/94829-owens-corning-introduces-foamular-ngx-insulation

    Reply
  5. Hi there! I’m curious how firm you and your partner are on using Foamular 250 (instead of 150)? I’m struggling to find 250 locally.

    Can’t thank you two enough for this site! Getting started on building out my 2020 Transit HR EXT and your build journal/instructions are top notch! 10 out of 10 for sure 🙂

    Thanks for the reply!
    -Rob

    Reply
    • 250 can take more pressure (weight) without deforming.
      150 would probably work since the plywood you put on top will distribute the load. Just don’t walk directly on the foam when building the van 😉

      Reply
  6. I’m curious what the standing height of your interior ended up being between the finished ceiling and snow chaser floor? This guide is proving to be an invaluable resource. I’m very grateful, thank you.

    Reply
  7. You haven’t fixed your floor? And when you crash which bit of heavy furniture would you like to be hit by first. Kitchen units. Bunks. And when your driving your vehicle will twist and move if your floor isn’t a solid base to build on to. Your cabinets and panels and anything else in there will move a lot loosening any strength in the fixings and opening up gaps all over the place.and unless your sleeping naked on your floor in -20 degrees then insulation under there is really not needed. Ask all the panel van converters out there with grade 3 insulation certified vehicles.

    Reply
    • The van was completed in 2017 and we’ve been using it full time since then (winter & summer); it works just fine. And with all the cabinets and structure fixed into the metal frame with crossnuts, the floor cannot go anywhere.

      Thanks for your input.

      Reply
  8. Just got started today buying gear and cutting the boards for our Toyota HiAce 4WD! Thanks so much for the inspiration, experience and brains behind all of this blog!
    We miss the vanlife we had in BC (and a brief stint in Oregon-Idaho) in a little Mitsubishi Delica 4×4 with a very basic setup and its “fridge” powered (or powdered?) with mountain snow 🙂
    Now we gear up a step, but not close to what you guys did!
    All the best from little NZ!

    Reply
  9. Antoine –
    I see that you ended your floor materials at the rear doors short of the actual edge of the van floor; this leaves a 5-6” area uncovered across the back opening.
    What was your reason for this approach? Would it provide better, more complete insulation & a level platform to have run your floor out to the edge of the van’s floor?
    I’m building a 2020 Ford Transit 250 148” Med roof.
    Great site you’ve built.
    Thanks in advance!

    Reply
    • This is to retain access to the spare tire mechanism, and also we didn’t see a reason to take it all the way back as this is not a living area. But I don’t see a problem if you want to cover the entire area, as long as you keep access to the spare tire mechanism.

      cheers

      Reply
  10. Hey Guys, thank you for the very detailed instructions on how to do this. I’m in the middle of doing it now on my 2020 Transit. Two questions about how you dealt with trim.

    The step up through the sliding door. It looks from your pictures like your step is just the tread piece, and does not have the ride and then the trim that would overlap the floor. Is that how your van came? OR did you trim the factory step? Mine is the full step w/ rise and overlap trim, just trying to decide if I should leave it the way it is and run the floor to it (in which case the floor will be slightly too high for the trim) or trim it where the tread meets the rise.

    At the front, there is a trim piece that runs the length side-to-side and again overlaps on top of the factory floor (I’m doing a Crew btw, but removing the factory floor in the front and doing my own ) did you remove this piece and take your floor right to the floor covering in the cabin? Or did you leave the trim and floor to the trim? Can’t tell from the pictures.

    Any comments would be awesome. Thanks!

    Reply
    • Sliding door: We have the factory step; didn’t cut anything. In fact, we would have liked to have the full step to get some kind of isolation, not only bare metal…
      Front: We only have a carpet that ends where we started our floor. Again, we didn’t cut anything.
      Sorry we’re not much helping on this one!

      Reply
  11. The silicon between my minicell and xps layers didn’t cure right after 2-3 days and the xps/plywood above it has been pulling away from it. Has anyone else has this problem? I may try to get the silicon off and then redo that layer with 3M 78. Any thoughts?

    Reply
  12. I am just beginning my build journey – and find your site very informative. So Thank you! I was curious on your thoughts on not filling in the corrugations with mini-cell to allow for airflow beneath the floor, or to allow somewhere for any condensation to disperse? Without the mini-cell do you think the XPS would gradually slightly cave into the corrugations and/or squeak more? Thanks for any insights

    Reply
  13. If you had an 8′ x 13′ sheet of vinyl, why did you cut it into two pieces instead of just trimming it and using a single continuous sheet? Wouldn’t that have saved the seam work?

    Reply
  14. Wondering when you said you would have done both layers of floor insulation (corrugations & layer 2) in mini cell, what density of foam were you planning on using? I see it come in 2, 3, 4, and 6 lbs densities. Having never seen it in person I’m wondering if it would be necessary to get one of the higher densities to prevent compression or a “spongy” feeling to the floor?

    Reply

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