In preparation for framing interior walls upstairs, we decided to first finish the tongue and groove wood. There were pros and cons to this solution. The pro that ultimately won the argument was that finishing the floor before there were walls there meant we could do it while it was all one open easy space without corners and crevices. The obvious con is that we have to be super careful while continuing to build on a finish surface.
:: We started by cleaning the space completely out and vacuuming carefully (using our fancy Festool vacuum that we're all a little bit in love with).
:: Then we sanded down high spots and repaired any blemishes in the floor we wanted to fix.
:: Once the floor was prepped, we got started with the large upright random orbital floor sander we rented from the local home improvement center. We started with 24 grit paper and worked our way down to 120 grit, vacuuming between each pass. This machine was really terrific. While it definitely took some strength to control it well, you weren't at as much risk of completely ruining your floor like with a drum sander. It also provided a much more even and beautiful surface, got very close to the edge, and still removed material relatively quickly. A great machine.
:: Before applying finish, we also sanded the ceiling of the tower so that the dirt didn't get sealed in.
:: While the sealant was being spread in even, gentle strokes from one end of the wall to the other to avoid piling in the middle of the floor, someone else was below on the plastic we used to protect the lower floor wiping up drips.
:: In total, two coats of shellac were applied. Then, the first coat of finish was applied. We opted for a low-VOC water-based polyurethane. It was an operation of forethought and careful coordination to get the urethane applied evenly, without drips, drops, and brushmarks. One person would lead, evenly pouring finish on the floor, and the other would follow with a wide applicator, spreading it from wall to wall, planning a route in advance to allow for a quick getaway down the ladder.
:: In between the 2 coats of finish, we screened the floor, vacuumed, and mopped with a tack cloth yet again.
:: When all was said and done, Eden said the floor looked like gold.
Doesn't this floor just make you feel like dancing?
It was tempting to plan a little hoe-down before we starting building walls upstairs. But, onward and upward! We only admired it long enough for the finish to cure, and then covered it with heavy construction paper to protect it while we continue to work.