Buying the Decking
I searched high and low for a good price on the decking. The plans call for 2×6 Tongue & Groove, preferably in 16 foot lengths. Yes, 2 inches by 6 inches. It sounded really thick, and when I started looking on Craigslist, I could only find advertisements for 1×6. I checked the plans- nope, 2×6. I called the orange box people – they don’t sell it, and can’t even order it. I checked local mills, but you need a large volume mill – the equipment to make it is expensive. I finally found a supplier in Guntersville- just a few miles down the road. They had it for about $0.95 per foot. I ended up paying about $8,000 for a bunch of it. They delivered and unloaded it for $25.
I decided after talking to another LHBA member to polyurethane the boards before I put them up. Otherwise, you can crane your neck and do it after they are installed. That didn’t sound fun, so I laid out all the boards on the ground and bought 5 gallons of water based polyurethane. I actually bought every gallon of water based polyurethane in town. Went to 3 different orange box stores and bought them all out. The blue people didn’t have any. Then I spent 2 days painting them all. Then another day stacking them back up into piles.
First layer is the hardest
If you set the first layer incorrectly, when you reach the roof, your decking will be all cockeyed and stuff. The only way I could figure to get it correct was to measure from the exact intersection of the rafters down to the ends of the rafters. I had to “scary climb” up to the Ridgepole, set the tape, throw the tape measure off the house, go down to the ground to get it, go back up the ladder and measure to the end of the rafter. I had to do this 4 times- twice for each end of the house.
Then I ran a string between these two points, and put a nail on the string at each point it touched the rafters. Then I nailed up the first boards, using these nails as stops. After about 6 rows, I had enough to stand on, and now had to think about getting the bulk of the 500 boards up on the roof.
After all this, when I got up to the peak, it is still off by an inch or two. I figure this is due to not all the tongues and grooves fitting together perfectly. In my defense, there’s about 60 rows of boards on each side of the roof. Stuff is going to get out of wack over that distance. No matter, I’ll trim the last board a bit, maybe add some flashing just in case, and nobody will be able to tell.
Getting it up on the roof
I tried sneaking it in through the gable ends, but as the rows got higher, I ran out of space. Then I tried with a pulley to pull them up using the ladder as a rail, and the tractor on the opposite side of the house. I finally just pulled them up with a rope and pulley and nailed a pressure-treated 2×8 nailed to the rafters to prevent the boards from gouging the already-installed decking. Video here.
Installation pattern & finishing up
The manufacturer recommends one nail per rafter, 4 foot spacing between rafters, and staggering the joints. The brochure shows a couple of options. I put 2 nails per rafter, and used ring shank nails and a nail gun and air compressor. I also used a skillsaw when necessary to cut the ends off. I still need to go back and trim the decking to a one foot overhang past the ridge pole and cap logs. That will be scary- out on the edge of the roof, sawing the ends off.
Since the rafters are 48″ on center (4′ apart), and the T&G decking is 16 feet long, things tend to match up nicely. Also doesn’t hurt that I made my rafters 5 inches wide instead of 4 inches wide- provides more surface to nail the decking.
I left the rafters with overlap at the peak until now- it’s too dangerous to trim the overlaps before the decking is on. A friend recommended not trying to pin them until the decking was close enough to the top to provide a place to sit while installing them. It was good advice- even with the decking up close to where I could stand while I pinned the rafters, and even with being tied onto the roof- that 65 pound jackhammer could jump off the rebar at anytime and possibly throw me off the roof. It ended up not helping anyway- that ridge pole made out of sweet gum is very very hard- the jackhammer couldn’t pound the rebar into it. I had to resort to my sledge hammer. Even then, I bent a few pins trying to hammer them into that tough wood. Video here.
Underlayment is either tar paper or a synthetic sheet that allows the house to breathe, but keeps the moisture out. Water gets out of the house, but can’t come in. There’s a lot of debate over exactly where to place the underlayment on a built up roof. Talking with other LHBA members, I decided to place it directly on the decking. Tar paper is good stuff- it’s been in use for a hundred years and works great. But it only has a 30 day UV exposure rating. Knowing how slow I’m going, I needed something with a better rating- the synthetic I went with has a 90 day UV rating. I bought 4 rolls of it: 1,000 sq ft coverage per roll. It was about $60 a roll.
Installing the underlayment means we’ve reached an important point in the build: for the first time, my logs are out of the weather since I cut down that first tree so long ago. It is a huge, huge relief to reach this point. During the first rainstorm after installing the underlayment, I just stood inside the house, listening to the rain, but not feeling it. It is very humbling and satisfying to reach this point. We’ve got a ways to go yet to full “weather proof”, but I’ll take a little victory lap for now.
Roof insulation and finishing the roof: I have to decide between solid foam and spray foam. Solid foam might be slightly cheaper, but I have to have a thicker roof- 12″ thick compared to possibly only 6″ thick if I go with spray foam. I also have to install “sleepers”, which are like ribs- they lay on the roof and provide a space for the insulation to lay in. The sleepers can just be normal 2×6’s or 2×12’s. Or engineered wood I-beams. OSB goes on top of that (if using shingles), or furring strips (if using metal roof).