Vertical siding, 1/2″ CDX nailing, and rain screens
Hi All,
Zone 5. Western Ma. First time owner/builder, building my own house. Budget is tight, skill set is limited.
I have the house framed, and fully dried in. 1/2″ CDX ( taped seems) , Tyvek, 2×6 walls 16″ o/c
I have a buddy with a sawmill, offering a deal on white pine boards for siding. Boards available are roughly around 12″ wide, various lengths. can be planed to uniform thickness, likely 3/4″.
My ideal plan is to do reverse board and batten. As to gain airflow behind the boards, and function as a rain screen. However, I’m not positive that 1/2″ CDX will provide enough nailing strength – Or will it? If I used hot dipped spiral shank siding nails? I dont want to put blocking in the inside of the wall (eat up insulation space), and I dont want to put two layers of criss/cross exterior furring.
My 2nd thought, Get boards from friend – Router shiplap on every board. Run horizontal 3/8″ – 1/2″ plywood strips every 2′ adding either shims/spacers, or corrugated plastic roll product behind the furring strips for air/drainage. The plastic corrugated roll only provides 1/8″ air gap – Will this extra layer of plywood furring be that much better for nailing?
Which do ya think is the better option?
Thanks!
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Replies
md1986,
I would do a modified version of your option #1.
Start by running your first reverse batten horizontally at the top of your wall, then the rest vertically below. The top batten gets nailed to the studs behind, and provides solid backing to nail your boards to at the top.
Thank you for the reply, Malcolm
Interesting idea! - That would for sure help for sturdier nailing at the very top of the boards. Would that horizontal batten restrict the air flow through the entire cavity, and impeed any drying?
Would you not be concerned about the rest of the boards being nailed only into 1/2 CDX?
mid1986,
Our code mandates rain-screens and allows us to fasten the furring to sheathing as long as it is 1/2" or thicker. That's what everyone does without a problem, and as that furring is typically at 16"oc, it has less support than your reverse batten would at around 12"oc.
I just suggested a bit of reinforcing because you seemed worried. Use ring shank nails and you will be fine. Some photos of doing exactly that on my own house:
Thanks Malcolm. - Looks nice!
Are the reverse battens in your photos installed over and into the wall studs at 16 o/c"? If so, did you then nail your boards into the battens? - Or are you nailing only into the sheathing for both batten and board? Are they wooden boards or a type of hardie plank type material?
It's my understanding (though opinions vary) that the board not be nailed directly into the reverse batten, but instead as close as possible to the batten to help pin the two together while still allowing each piece to move individually with expansion/contraction. Does that sound like the right idea?
md1986,
Mine is Hardi board with Hardi battens (not reversed). I just posted it to show the holding power of furring that is only nailed to the sheathing. A 4'x8' Hardi panel weighs 80 lbs without the battens.
It is a good idea to use a nailing pattern that lets the boards move to avoid splitting, but the advice I've seen is to nail one side through the reversed batten (which helps with the vertical loading) and the other beside to let those fasteners flex a bit.
So neither the furring or the Hardie board is nailed into the studs in your photo?
Its not the so much the weight of the pine boards I'm concerned about, its the cycles of expansion and contraction strength over time, something that the Hardie board doesn't add to the equation. A 12" pine board will have a good deal of seasonal movement - I'd just love for the 1/2" CDX to be enough nailing to contain it over the years! Screwing down a few loose boards here and there is not a problem. But if they all started falling off, well that's clearly a different story.