Absolutely FLOORED: Laying a New Subfloor in a Vintage Airstream

Kristin laying on Airstream subfloor

With the frame prep work finally done – after what seemed like ages – it was time to install the new trailer subfloor! I don’t even remember what it was like to walk in the trailer without balancing precariously on steel beams. I have a new respect for gymnasts, for sure.

Mind the gap! These beams are about 3 feet off the ground.

The wood for the subfloor was purchased from a local lumber yard. I chose 1/2″ 5-ply exterior-grade sheathing that was cured and stored indoors for a long period of time. The flatter and drier the wood is, the better the floor will install and last over time. Wood from the “big box” hardware stores often isn’t cured long enough or stored out of moisture, so it becomes warped, or shrinks and expands after installation as it dries out.

Jeffries Wood Works calls themselves “Lumber Heaven”. I can see why: it was so much fun to browse everything they offered!

After a lot of research, I opted against marine grade wood and instead am treating it with a borate-based (non-chemical) pre-treatment from another local company, Nisus, to prevent mold, mildew and insect infestations. I doubled up the floor’s protection by sealing the bottom and edges with a low-odor (and VOC), oil-based primer.

The actual finished flooring is going to be 12″ x 24″ cork tiles glued directly on top of the subfloor.

Cork flooring tiles Airstream

I was very grateful to be able to borrow a family member’s wood shop (thank you, Tony!) and tools to cut the pieces of subfloor. If there’s anything I’ve learned from renovating a 100-year-old house and now this nearly 50-year-old Airstream, it’s to never assume anything is square, plumb or level! Even after careful measurements and templates, there were still a lot of adjustments to make when the time came to install it!

Would ya just look at that beautiful slab of wood! 😍 “Measure twice, cut once” goes out the window when you’re dealing with a non-uniform, 50-year-old trailer: lots of tiny adjustments on the fly happen instead!

Using sheets of foam insulation as a template for cutting the rounded floor corners worked quite well. Those will be reused later to insulate under the subfloor. It was easier to test-fit the insulation – and shave off any adjustments to the curved parts with a knife – than to keep cutting the actual plywood incrementally to fit.

Foam insulation used as a template

With several helpers to stabilize the trailer and position the flooring, we jacked the Airstream shell up off its frame a few inches to be able to sandwich the new flooring between the two halves. 2×4 framing and poles were used under the sturdiest ceiling support beams, at the the front and rear of the trailer, connected to floor jacks on the ground.

Floating frame!
The first piece of floor in place, in the front of the trailer
All sections of flooring are dry-fitted. The middle seam is a bit raised because it’s not bolted down yet.

Installation took two days, several people, lots of wiggling, cursing, and adjustments with a sander and jigsaw – but it’s in. It was a terrifying experience, watching all that aluminum teetering around freely in the air! I am not one bit upset that it’s safely back down on the floor and frame now.

I’m also so excited just to be able to easily walk inside the trailer again for the first time in many months. It was also the dogs’ first time ever in the trailer, and my first time sitting or laying down on the floor, just because it was too icky to want to previously! 😆

Bolted down now! The wheel-well cuts aren’t beautiful, but we needed the extra wiggle room to lower the flooring in, and those will be built into cabinets and have insulation covering them anyway.
The doggos’ first ever Airstream visit! And I couldn’t resist starting the layout planning with some masking tape “walls”. The chair is the future toilet. 😆

One very exhausting weekend later, another huge job is off the list. Time for some much-needed rest! 😴



  1. Cameron
    Aug 30, 2015 / 2:33 am

    What is that black spray you used on the seams? I have been looking for someone who has had luck with something like that before I put my inner skins back up. Thanks in advance!

    • Kristin
      Aug 31, 2015 / 6:30 pm

      Hi Cameron! I added some spray on rubber that’s used for lining leaky gutters on houses. I’m not sure how much good it did since I didn’t have any major water leaks even when the skins were out, but I figured it couldn’t hurt. Then I sealed the exterior seams as needed where the caulk had cracked with this clear sealant http://www.captaintolley.com/.

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