Oak Board and Batten Siding

Oddman · April 03, 2022, 03:45:57 PM

We are building a 2,800 sq ft community building for our church. The siding is all red oak board and batten and I thought I would share how I sawed the siding as well as how it was prepped and installed.

First step was deciding the size of the boards and battens. We went with 10" boards and 3" battens, 3/4" thick. It looks proportional, has good overlap of the battens for weather proofing, and gave me a manageable log size to target. (Larger boards = larger logs needed)

So small end on the logs needed to be about 14" to get a decent amount of siding, most of them were around 15"-20".
Turning a 20" oak, 10'6" long on a manual mill is alot of work. I bought the largest cant hook that logrite sells and it was well worth it.
After getting the log on the mill and deciding where to open it, i would level the pith. Open that face, turn the log 90°, level the pith again. While some knots and defect was acceptable to us, I did my best to keep the boards to the best grade I could. My target was a 10" wide cant. I can't remember my drop chart (cheat sheet) at the moment, but i made one up for 3/4 boards. So once the log is turned twice, opening face is on the deck, I would need to know what face I wanted to take boards off of. If it is face 1 (opening face), then reference the drop chart to set the height of the 3rd face cut, if it was face 2 then go to 10" then work up in 7/8 increments to the best place to open the 3rd face. I find it helpful to use a can of marking paint to spray a line across the end of the log in same plane as the boards, to help me remember which way the cant needs to be oriented for sawing the boards off. Once i had the cant ready for sawing boards, I would saw all the way to the deck without offbearing, unless i ran out of throat room, which is about 12-13" on my mill. This keeps the cant flatter on the deck for me, helping to counter the stress, especially once your into the bottom half of the cant.
So the cant is sawed into 3/4 boards, all except the bottom board, which is 1 5/8" thick. My mill will only saw down to 1" so i will offbear the boards, taking the last 3/4" board and the bottom one, turn over the 2 keeping the sawdust sandwiched between them, clamp them carefully, and saw the 1 5/8 piece into 2 boards. An alternative to that, depending on how your batten/board ratio is looking: saw your cant but leave a 3"x10" with the pith centered. Take the 3x10 and saw it into battens. Typically the battens containing the pith are junk so you have a couple to throw out but this method will probably leave you with more slightly more battens. My normal method involved taking the flitches and sawing them into battens as well as any boards that contained pith or another large defect. For instance, a board with pith will still yield 2 battens. Remember shorter boards and battens will be needed for around windows/doors, etc so there is little waste involved here.
That gets us pretty well started for one post, I'll be back later to add more.

Dragline · April 03, 2022, 04:53:54 PM

Great write up of your process. I've been thinking about milling some white oak board /batten siding, but I'm worried about splitting. Are you installing green? How will the boards be attached? Will be following your progress.

customsawyer · April 04, 2022, 05:39:25 AM

In sawing lumber like that I normally saw it 7/8" thick. This way you wouldn't need any cheat sheet and you can change the way you are cutting a log on the fly if some stress starts to show. It just ends up being simpler. Your boards will be a eighth of a inch narrow but it is going to shrink anyway.

thecfarm · April 04, 2022, 05:47:54 AM

I did a horse run in with 10 inch boards and 4 inch battens.
There was a building on the way to work that was built like that. Took me 6 months of driving by to see someone outside. I stopped and asked about it.
He bought a bundle of wood with 10 and 4 inch boards, so that is what he used. I like the way it looks.

Oddman · April 04, 2022, 02:18:37 PM

So wev got a log milled. We brushed all the sawdust off the boards prior to delivery to the building site. On a previous smaller project we did not do this and it stains the boards up and they end up ugly. Also while handling the boards here is a good time to use a knife to take off any bark on the edges, get it down to the sap wood, don't leave the inner layer of bark.
We installed this stuff as green as possible. After milling/brushing, we select the side of each board that will be the exterior and sand it with a palm sander at 60 grit. Just knock down the rough stuff here, don't need to get crazy. The battens will need their face and sides done as well as any "scraggles" on the corners from the milling will need knocked off. You will need to determine if you will select the face that shows better grade or if you want to install all boards uniformly, ie - alot of folks recommend, me included, to install the side of the board that was toward the outer part of the tree towards the exterior of the building. As the board dries this will cause the center of the board to remain tight against the purlins/wall and the outer edges to curl outward and tighten up against the battens.
We took the time to staple a piece of tin flashing on what would be the backside of any knot holes, cracks, or knots that looked like they would rot/fall out.
As we process the lumber we lay it all out on 2x4s strung over multiple sawhorses in preparation for stain. We put on a fairly thick layer of stain, (the battens get their edges as well as face stained) and once that dries the siding is ready to install.
The method of attachment that we chose was 1 galvanized rink shank nail out of our air nailer shot into the center of the boards at each purlin. The boards are put up tight to each other knowing they will shrink, the battens then go on with 1 exterior deck screw aimed between the edges of the boards, at each purlin. 2 nails on the boards can cause splits as they dry unless they are set pretty close, same issue with the battens, also we feel the screws are good for the battens given they hold well and can easily be tightened up later if needed. Any fasteners used that are not exterior coated or galvanized will likely show acid streaks later if that is a concern to you.
We found it handy to mark the spacing of the purlins out on each batten and pre-drill each hole prior to install. You will find that the boards go up quickly with this method and the battens take a fair amount more time. Don't delay too long between the installation of them, as the boards will curl a fair amount if they aren't battened within a day or so, depending on how much sun they get. We would typically mill up a couple logs then get them prepped that day or the next, and installed right away.
There are more details I will share soon, thanks.

Oddman · April 04, 2022, 02:27:45 PM

Quote from: customsawyer on April 04, 2022, 05:39:25 AM
In sawing lumber like that I normally saw it 7/8" thick. This way you wouldn't need any cheat sheet and you can change the way you are cutting a log on the fly if some stress starts to show. It just ends up being simpler. Your boards will be a eighth of a inch narrow but it is going to shrink anyway.

I agree with you here crossroads. We decided on 3/4 figuring it would be thick enough to be durable/long lasting and know it would save our limited resources for this large of a project. 1/8" across this many boards does add up to a fair amount. Also a 10" wide oak board of any appreciable length is fairly heavy so thinner did ease the install some. That was our reasoning anyway, each will need to weigh all that out on their own.