Sanding the floors
After we finished most of the interior walls, we spent over a month sanding the floors to prepare them for polyurethane. The pine planks had gotten cupped, dirty, and discolored from exposure to sun and rain last summer before we got the roof on. We could have gone the easy route and painted the floors, but we like the natural wood look and decided to do the extra effort to preserve that look.
The first step was to rent a drum sander to take off the worst of the discoloration and smooth out the transitions between planks.
This kind of sander is generally not recommended for pine floors, but the suggested alternative, a three-disk rotary sander, didn’t work for us: it didn’t start when the temperature was near freezing, was hard to steer, and made a striped pattern on the floor. The drum sander did the job, but we had to practice a fair amount before we got better at not leaving valleys and ridges in the floor. This required keeping a very steady pressure on the floor, keeping the sander moving at all times, and raising and lowering it very slowly. It took us about a week to get the 1550 square feet of floor done.
The next step was to rent an edger, a kind of heavy duty rotary sander for finishing the edges of the floor where the drum sander couldn’t reach. This was hard work, too, because it had to be done on hands and knees, and because the sander was very powerful and wanted to tear itself out of our hands.
Even the edge sander couldn’t get into the corners, so for that we used a quarter sheet random orbit sander, which has a rectangular shape. We ended up using this sander, plus a rotary random orbit sander, to do the final sanding. We had thought about using a rental sheet or screen sander, which came in either 13 inch or 17 inch sizes, but we were concerned about controlling such a large device for the fine work. So we hand sanded the floor for two weeks, getting ourselves and interior of the house covered in a fine layer of dust.
The quarter sheet sander was not able to collect any dust at all, but the rotary sander did a pretty good job, collecting maybe half of the generated dust.
Finally, we had to spend several days vacuuming the floors, walls, and beams to get rid of the layer of dust that coated everything. We didn’t sand where the kitchen cabinets will be, and the difference is quite striking.
The floor looks good now, and is smooth to the touch and to bare feet. The next step will be the multiple coats of polyurethane. We’ll wait for warmer weather, which should arrive soon.