Before you can install your flooring, you’ll need to install a flat substrate to attach it to. This post will teach you how to install a wood subfloor that will become the base for everything else in your van build.
What You’ll Need:
*Disclaimer: As an Amazon Associate I earn from qualifying purchases.
Caulk Gun and Construction Adhesive
Cardboard Scraps
Mold & Mildew Resistant Primer
Paint Supplies (brushes/rollers, paint tray, drop cloth)
Insulation
Drill
Installation
Step 1 – Furring Strips
This step is repeated information from our post on framing your van. If you’ve already framed the floor with furring strips, skip to Step 2!
The first step is to install framework to give the subfloor a flat bed to rest on. We used 1-in x 2-in x 8-ft furring strips and cut them to length. Before installing them, we covered them in a coat of mold and mildew resistant primer. To secure them in place, apply construction adhesive with a caulk gun and adhere them directly to the metal of the van floor. Add weight to the top for at least 8 hours while the adhesive dries. We used bricks.
Step 2 – Create Templates
Cargo vans don’t have perfect 90-degree corners, so you’ll need to cut some irregular shapes to create the subfloor. This can be achieved by first creating cardboard templates. The best method we’ve found to replicate the curves of the van goes like this. Outline the curve with small strips of painter’s tape, then carefully peel it up and transfer it to the cardboard. Trace that outline with sharpie and cut the cardboard along your outline. Don’t throw out these templates once you’re finished with the subfloor, because you can use them again when you install the flooring!
Step 3 – Cut Plywood
We used three 4’ x 8’ x ¾” pieces of plywood for our subfloor. The diagram below shows the dimensions of each. Keep in mind these are the dimensions we used in our 159″ wheelbase Ram Promaster. Dimensions will vary slightly depending on the model of your van.
Trace your templates on the wood and use a jigsaw to cut along your guide. Ere on the side of cutting too little because you can always come back and cut more. Once you’ve cut the wood, bring it back to the van for a test fit. Unless you’re an absolute pro, you’ll likely need to bring it back to the cutting board and make some adjustments before it fits perfectly.
Step 4 – Prime
This is an optional step, but we do recommend it. Adding mold and mildew resistant primer creates a layer of protection against moisture, which will prevent mold. We used Zinsser Bullseye 1-2-3 , and another great option is Kilz. Paint all the edges with at least one coat. This was the most time-consuming step for us!
Step 5 – Insulate
Some van builders choose not to insulate the floor because warm air naturally rises to the ceiling. In cold temperatures, your ceiling insulation will keep that warm air inside the van. And in hot temperatures, a ceiling fan can push warm air out while cool air is pulled in through a lower ventilation source.
We agree that the floor is the least important surface to insulate, but we still recommend it. Having a fully insulated van prevents heat loss and gives you more control over the temperature in your home on wheels. If you’re on a tight budget, you could choose to prioritize insulating the walls and ceiling.
We insulated our floor with Havelock wool. We have another post that goes more in depth on why we chose this product as our insulation. If you’re interested, you can find that here. Each Havelock box comes with 20 batts of wool, and we used 5 on the floor.
Cut the wool into strips that fit between your furring strips. The bats of wool are thicker than our furring strips, so we peeled them in half. This can be done pretty easily by hand. No need to adhere them in place, just set them between the furring strips, and the subfloor will hold them in place.
Step 6 – Place and Trace
Place the pieces of plywood subflooring one at a time. Before you place the next one, look below and mark where your furring strips are. You’ll need to know where to insert the screws. We marked the location on one end and used a T-square to draw straight lines to the other end.
Step 7 – Secure
We used about 100 flat Phillips 1-1/4” wood screws to secure our subfloor. Use a drill to insert screws along the furring strips, which you’ve outlined on the plywood. We placed the screws approximately one foot apart. You can insert the screws directly through the plywood and into the furring strips, there’s no need to drill pilot holes.
And then you’re finished! You’ll now have a flat surface to lay your actual flooring. Speaking of which, we’ve covered flooring installation in this post.
Total install time: 9 hours
Drop us a comment or DM us on Instagram if you have any questions or just want to say hi! We’d love to hear from you 😊
Looking for more camper van conversion tutorials? We’ve outlined each step of the process on “How-To Guides” tab of this website. Please reach out via my contact page if you have any questions or want to share your experience!