Flooring system

I’ve made five trips up the mountain since I last wrote: once in March, twice in April, and twice in July. My main objective has been building, specifically (1) the floor system, and (2) framing for windows and doors. In this post, I talk about the first of these.

At the time of my last report, the structure consisted of two timbers on each of the West and East sides, and one timber to the North and South — an exciting development at the time, but hardly a cabin.

I had originally supposed I would build the outer structure (walls and roof) before beginning on the floor. Two circumstances caused me to change my mind. First, the boards needed for my floor joists are wider than any of the timbers needed for the wall structure. That is, they must come from the largest logs that I have harvested. I am wary of taking all the choice logs and milling them to the size of my timbers (8.5x 5.5) and having nothing of substantial size left for my joists. Second, those boards that I have already milled, many more than a year ago, are beginning to warp and twist as they dry, despite my efforts to prevent this through careful stacking, stickers, weights, etc. Therefore, I decided that it would be advisable to prioritize the milling and placing of floor joists.

My original plan called for 12″ joists, but I discovered that boards this large are hard for me to come by. Reference to the American Wood Council span calculator convinced me that my twelve-foot span could in fact be accommodated by 10″ boards. What is more, my 2x10s are the full rough cut size, rather than the smaller size of dimensional lumber from the lumber yard, which has been dried and planed. Furthermore, since the joists need only be precise in the dimension of their length (along with a smooth supper edge, of course), as I was milling I found that sometimes I might be able to obtain a 2.5″ or even 3″ thick board. Using these will only increase the strength of the floor system. I, therefore, adjusted my plans accordingly.

Base layers and ledger boards

In March, I was able to spend the better part of a week working on the cabin. I was solo for the first several days and focused on skidding and milling, especially aiming at those large logs that could be fashioned into joists. On day five, I was joined by my friend John Parham, among other things allowing me to replenish my food, which was running low, and bring up five gallons of fuel.

John was keen to start on the floor system so that is what we focused on. My design was to install a ledger board along the bottom edge of each of the East and West walls. With 10″ joists, the floor would be approximately 15″ above the bottom edge of the lowest log (4″ ledger + 10″ joist + 5/4″ floor board). This required two levels of logs all the way around before beginning on the floor. For good measure, we also placed the third log on the East and West walls (the walls where the joists would be adjoined to the wall).

After shaping and placing logs on the shorter North and South walls, we attached the ledger boards using 5 3/8″ lag screws. We drilled pilot holes in both the ledger and the walls. In retrospect, we probably should have drilled the ledger holes wider as the friction from the green wood on the lag screws was tremendous and we sheared off a few of the screw heads in the process. Even so, I was reasonably satisfied with the tight fit of the ledgers to the uneven, rough-cut wall timbers.

Altogether, we installed four 2″x4″ ledger boards, two on the East wall and two on the West wall, each with a small gap over the T-bracket to the foundation.

Installing the joists

I returned at the end of the month with two college friends, Jonathan Davis and Brian Carlisle. By this time, we had enough 10″ boards for approximately half of the joists. Due to the placement of the T-bracket on the center foundation pillar, there could be no joist right at the center of the cabin, so a larger gap of approximately 24″ was left there and the joists were evenly spaced throughout the remaining distance to the end walls with some of the thicker joists used adjacent to the gap.

This was to be a short trip due to all of our work schedules, so we worked fast. One of us would pore through the piles of rough cut boards to find those that fit our needs. As these were sourced, the others would shape them for the joists, which were laid on top of the ledgers and held into place with a 30-Penny ring shank pole barn nail toe-nailed from the top into the third wall timber. We used scraps to block the floor joists approximately along the mid-line.

A third trip, this time accompanied by grad school friend Bryan Bademan, and a forth trip, with Rico, were required to finish the floor system. (This slow progress is partly explained by other setbacks this spring, such as the complete loss of the motor on the Hud-son, which I have yet to write about.)

During a four-day trip in mid-April, Bryan and I managed to skid and mill just about all the remaining boards that would be needed for the joists, and much of the floor. Then, in July, Rico and I returned and completed the joists along the pattern that I had established in March, i.e. a joist every 18″ at least 2″ thick and sometimes more, blocked at the mid-point with as large a board as we could find.

We also lag-screwed a 4″x4″ board to each of the North and South walls so there would be a nice stable platform to support the ends of the floorboards. I figure that since these boards don’t actually span the 12′ distance (they are fixed to the wall), they don’t need to be the same width as the joists. In fact, they seem to be very stiff and I think will greatly help the stability (i.e. reduce bounce and prevent board twist) of the floor.

Flooring

I love the look of wide, rough-cut floorboards.

With Bryan, I began selecting the choicer subjects from my stockpile, and with Rico we started to install them. My intention was to use 5/4″ lumber for all of the flooring, but my milling is not consistent enough to allow that. In practice, I determined that anything between 1″ and 1 1/2″ would be acceptable. For a rough idea of what would be required, Rico and I took the boards we had and laid them out on the joists. It was an exciting moment, beginning to imagine how the inside of the cabin would look and feel.

Then we began the arduous task of shaping the boards. My milling simply isn’t precise enough to simply place the floorboards edge-to-edge and nail them down. I toyed with the idea of milling them in some kind of overlapping bevel or shiplap but decided that the thin edges would be simply too fragile. Instead, I opted to shape each board and simply place them as tightly as I could.

I think of the boards as running in “lanes” from one short end to the other. I do not require that the lanes are equal in width. In fact, I think that variable-width floorboards are rather charming. And, to minimize the number of boards I require, each lane should be as wide as possible.

My process is as follows. Starting with a lane along one of the long walls (East and West), I identify the two or three boards that will complete this lane. I then determine the minimal width of these boards, say 10″. I then scribe a straight line along one of these boards and cut it using the circular saw to provide as straight an edge as I can obtain. Using a carpenter’s square (for distance) and a five-foot piece of angle iron (for straightness), I mark a line parallel to the straight edge, which I then cut free hand with the circular saw. I repeat the process for each of the other boards. I then lay out the boards end-to-end, cut them off square, and screw them in place with deck screws. Placing a lane takes approximately 75 minutes. Seventy of these minutes are shaping and five are screwing it down.

As of this writing (August 13, 2023), I have completed about two-thirds of the floor in this fashion. In the picture below, you can see how much has been completed (along with my “ground cache” of tools, camping gear, and equipment, which has been moved from the campsite to the cabin in the hopes that it will be safer from rain and rodents).

It has been hot here in Georgia and I am eager for the cooler weather of fall. And eager to finish the floor. And eager to focus again on the walls.