In 1839 an English poet by the name of Elizabeth Barrett Browning wrote a letter addressed to fellow poet Richard Henry Horne in which she wrote, “The luck of the third adventure is proverbial.” In 1862 the Free Church of Scotland minister Alexander Hislop wrote “The third time’s lucky.” These two instances are believed to be the precursor to the phrase “The third time’s the charm.”

Flooring… Like most things beneath our feet, it’s taken for granted. You walk on it, sweep it, your cat Katy Purrrry (Walter Croncat for you older generations) lays on it, and it all seems very simple. We didn’t just go out and buy materials and start cutting. We actually planned everything. We wanted to make certain that our floor would be sealed and that we would never have to deal with any moisture problems down the road. Overkill is perfectly fine when dealing with a project such as this.

We went with several different layers and it ended up quite nice. A trip to Sherwin Williams and a talk with the associate there led us to DTM Marine Bonding Primer. This was an expensive purchase at $100 but well worth it. They can only sell it to contractors but an exception was made for us. It is used for sealing anything indoor or outdoor. After that was dry we used 6.4mm automotive plugs to fill the 480 holes in the floor from the track seating. Using a tiny bit of silicone on each hole for extra precaution, we hammered the plugs in tight. A gallon of Flex Seal was used to paint over them and the DTM primer. Once that was dry we used several tubes of Gorilla Glue and laid down 6-mil plastic sheeting. Finally we could start laying down the sub floor.

For those that do not know, most lumber sold is not the dimensions they are advertised as. When a board is first cut it is true, but the drying process and planing reduces it. A 2×4 board ends up being 1.5×3.5″. When you are buying lumber make sure to check the tag for the “Actual” size if you are needing something more specific. There are true 2x4s that are sold.

Using a Makita table saw we started to plane down a bunch of 2x4s ourselves, taking .5″ off of the ends. This was so we could use 1″ foam board insulation without having to worry about proper fitment. Unfortunately a dull blade, not enough air flow, and pushing the boards through too fast burned up the $600 saw and the project came to an abrupt halt. After sourcing an industrial table saw a few days later we finished planing down the boards, keeping the scrap .5″ pieces for trim work.

We placed a 2×4 stud on the floor every 4′ so that we did not have to worry about cutting the 4×8′ sheets of OSB board. Once we were done the OSB sheets were laid down but the floor was very soft. We thought we could live with it but the more we walked on it and thought about it, the more we realized, if it’s not right now, it won’t be right later. We took the OSB boards out and ran another set of studs vertical from the front of the bus to the back right down the middle. The middle of the bus is going to be the hallway which means a high traffic area. Since the foam board insulation was already laid down, this was accomplished by cutting the studs to the appropriate length, tracing them with a sharpie, and using a box cutter to cut out the foam strips. Once the foam was cut we used a flat head screw driver to pop up one end of the foam and run our hands down it popping it out as we went. This worked extremely well. The OSB boards were laid down again but the floor was still soft. At this point we realized that if we kept adding studs the floor would gain strength but would start getting colder due to lack of insulation. What else could we do but pull the OSB boards up again?

After watching a bunch of episodes of This Old House, we noticed that not only the walls, but the floors were 16″ centers, meaning from the center of one 2×4 to the center of the next 2×4, was 16″. We decided that we needed some sort of horizontal support between the 4′ sections.

We took all of the OSB boards (3rd time) back out of the bus and added more studs running parallel with the horizontal studs. These studs we cut short so that there was plenty of insulation around them and the other studs. Spray foam was used to “glue” and seal around the shorter horizontal boards. The OSB boards were put back in and wouldn’t you know it…  still soft on the ends.

The boards were taken back out (why are you still reading this?) and additional vertical studs were added to the ends of each 4″ section. Teks Self-Tapping Phillips-Drive Exterior Wood Screw were used for all of the studs except the shorter horizontal ones. The OSB boards were put back in and the floor was solid. Except… you know what? we forgot to tape all the seams. Hahahahahaha! We love it ser murch!

The boards, they were taken, back out, again… Reflectix tape was used to seal every crack and Reflectix 4′ Roll Insulation was placed down on top of it all before the OSB boards went back in and screwed down to every stud. It was finished.

This floor is now water proof, over insulated, and incredibly sturdy. All we can say is…

5th time’s the charm!

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