Vertical Cladding Install Options
I’m looking to utilize vertical cladding for a new build, but don’t want to pay the premium for composite or thermally modified material like NuCedar or Accoya, etc. – both of which utilize a pretty straightforward install with board cuts at random lengths and staggered butt joint connections, all on top of a furred rain screen, of course. (Attached a reference image for design/aesthetic preference)
However, other less premium products like Hardie Artisan shiplap (which can be installed vertically) state in the install instructions that you cannot utilize butt joints, must use full boards rather than random lengths to stagger the joints, and require Z-flashing across the entire single horizontal joint.
Obviously I know that you can bypass these instructions with a good rain screen and wrb, but I’d rather not void any product warranties.
My goal is mainly to span a 2-story gable without a visible horizontal seam (random butt joints are far less obvious). I’m really against having a single horizontal control joint.
Is there another creative solution that I’m missing that helps avoid having to use a single continuous horizontal z-flashing joint? (I.e. belly banding) Or another moderately priced option that I could utilize?
P.s. – The only other moderately expensive route I’ve considered is using trex/timbertech PVC cladding and using butt joints like you’d use for Accoya, however I’m not the biggest fan of the aesthetic of these products (high gloss and poor color/texture options imo).
Alas, maybe this is just the reason folks utilize horizontal lap siding everywhere 😂🫠
Thanks for any and all help!
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Replies
How about cutting the shiplap so you end up with random lengths. At each joint, add a short length of color matched Z flashing same width as the siding.
This gives you the random look without a horizontal line but stills follows the instructions.
Thanks @Akos, and agreed - This was my initial instinct, but I was worried about if Hardie would still warranty this assembly AND normally z-flashing requires a larger vertical gap between boards, which might defeat the whole purpose of 'seamless' butt joints...
Houses tend to move that is why you don't see cement panels longer than one story. Asking for cracked siding if you do that. One way to avoid this is to install horizontal metal Z furring which allows the building to move without effecting the siding. You can get these perforated with allow for a rain screen gap without any additional wood layers. Ie:
https://www.phillipsmfg.com/z-furring-channel/
The color matched Z flashing will not be noticeable at a distance especially if at random location. The 1/4" gap will disappear into the shadows. I don't see any issues with shorty Z instead of a long continuous Z. They both serve the same purpose. You still would need to decuple the siding from the house as above.
If you want long seamless, there are many metal panels that can be run the full lengths. More cost but tend to be quicker to install if your shape is simple and not too many windows.
This is a great point - it hadn't occurred to me that movement might be the issue, as opposed to moisture management, but makes complete sense for fiber cement.
In that case, I suppose that the z-flashing also serves to create durability against movement, instead of moisture, as I assumed.
Interestingly enough, I talked to Hardie and was told that, generally speaking, if their product fails because of moisture, it will void the warranty anyways...which I found odd. Either way, they didn't recommend the install method you stated above, but then again, what manufacturer is going to sign off on this type of creative install?
I think this method could be the only real option, without changing to a composite or wood based product. Funny enough, I came across Azek (pvc) siding agaiin yesterday, and realized that they are manufacturing vertical siding under the 'TimberTech' brand. I haven't priced it, but if it's similar in price to normal TimberTech decking, it'd be dramatically more cost effective when compared to Accoya or Boral, for instance.
I don't understand the resistance to a natural joint. A simple scarf joint will look and perform just fine in any wood. I avoid fake or heavily engineered materials when I can and prefer to use locally-sourced materials, which limits my options, but I see that as a benefit, not a problem.
I don't have resistance to a simple joint - in fact I'd prefer an open scarf joint, (which is what is spec'd for products like Accoya) however this looks to void the Hardie warranty.... Hardie requires a single horizontal seam, and z-flashing across the entire length. They even state in the install instructions to not use butt/scarf joints & also require that you caulk the shiplap seam between every board....
Not an issue if using hardwood or a thermally modified product like Accoya, but those cost an insane amount :(
If you aren't in a highly bug-prone area, I've found that vertical white pine with a robust rain screen gap performs very well, even without finishes, but with stain, paint, or Valhala's Lifetime Finish, it should last a very long time with little maintenance.
I would not push any limits with Hardie siding. It's vulnerable enough to moisture as it is.
This sounds like a great alternative, although I've always worried about using real wood. I'm in a very humid and bug-prone area (termites included) unfortunately, so Hardie is kind the standard here...hard to be the durability and price point.
Great suggestion Michael - I was going to recommend as well. I've also found it to be extremely cost effective even compared to budget siding options. Note that even with a sealer or stain, I have found in my personal experience that it can and will weather and gray differently depending on facade due to elements and sun exposure. To avoid this you could use a weathering accelerant to even the graying if you are going for a uniform look and are OK with the gray.
Thanks. Unfortunately it's not a great solution where there is high termite pressure. Have you looked into Lifetime Finish by Valhala? It instantly ages the wood, it's non-toxic and supposedly lasts pretty much forever: https://valhalco.com/
I don't know what lengths the Hardie is available in or how tall your gable is, so this might not work for you. But on a small cabin, I was able to avoid joints in the vertical board and batten by strategically locating and sizing the windows to keep every siding piece under 16'.
Unfortunately I need to span two full floors that will end up being 24' at the peak.
Rainbirdd,
It's of course an individual preference, but I never run siding over an area taller than one story and a gable. If I had been designing the house in your first post I would have broken up the cladding into two types at the second floor, with the bottom one having a more solid feel to ground the building on the site.
Generally I'd agree, especially from a functionality and install perspective however the main goal of this is to get a completely seamless appearance.
Rainbirdd,
I would look at the installation details of wood-based composite siding. You may find one that allows scarf joints. Cement-based ones won't, and PVC ones will have too much movement.
Yes exactly - my issue with these products is mainly price. They're definitely my preference, just can't afford them. I'm a big fan of Accoya, for instance, and a company called Millboard makes a nice composite as well.
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TruExterior and Modern Mill Acre siding may be choices too. I think both be scarfed or rabbeted at joints from what I remember from the install instructions, although I haven't personally used either. The Acre is rice hulls filler with PVC, and the TruExterior is polymer and fly ash (very different than Hardie).
Neither are cheap, but both are 3/4 thick (or close to that, can't remember) so are a rather thick siding product compared to commodity Hardie.
Ya I'm a fan of Boral (rebranded as Tru exterior) however it's super expensive at $80 + for a 16' stick...hard to find a moderately priced product that fits the bill to be honest. I know Acre is similar in price to NuCedar.