Fastening Siding to Zip R-Sheathing
drewfridley7
| Posted in General Questions on
I am planning on using Zip R-Sheathing. I have read the fasenters should not compress the insulation. How is any kind of siding installed over the sheathing? I do not understand how or where I would fasten it if I cannot attach it to the Zip system without putting holes in the continuous thermal break and/or compressing the exterior insulation with fasteners?
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Replies
Drew,
https://www.huberwood.com/uploads/documents/technical/literature/ZS_R-Sheathing_Installation_Manual-R3-12v21.pdf
This is just my opinion -
don't think thick Zip R sheathing has much of a place, well, anywhere. It only provides a fraction of the shear capacity as a nominal 7/16 rated structural panel, and that's even if you can get it nailed right. It doesn't really provide a good nailing based for anything, as it's so thin. It's too thick to nail through to the studs accurately, and even if you could, you've got a nail every 2-4 inches that's in the way. Those studs have more nails in them than my local home depot.
For the thinner panels, R3, everything is much simpler. But thicker, and I would consider going the opposite route, and using exterior insulation + furring strips on top of sheathing. It just provides an easier utility for attaching the siding, and keeping the details construction friendly.
You're saying you'd recommend the 1-inch ZIP R-Sheathing? But not any thicker? I'm not familiar with the furring strips on top of the ZIP. Do you have a video you would recommend? Thanks for your wisdom!
Drew,
What I’m getting at, is that ideally you want your sheathing to be in contact with your studs, and the further you move it outwards, via the insulation thickness, the worse it gets at everything it is supposed to do. That is why I said some of the thinner panels would works fine, and behave nearly like normal sheathing. After all, one inch total thickness isn’t really all that different from 1” board sheathing that used to be common place. You can attach siding through it to the studs fairly easily, and for the most part you don’t know the difference between the combined insulation and sheathing (zip R), and normal plywood or osb.
I would put it this way: I would feel comfortable using the zip R3 panel as if I were using a sheet of commodity osb. If that met the insulation requirement with the combined cavity insulation, then everything is great.
However, if that total r vale was below my requirements, then I would scrap the zip r sheathing all together, and use regular zip, without the attached insulation, or plywood and osb with a weather resistant barrier like tyvek, typar, or barricade, and place insulation outside of that. That insulation can be XPS, Polyiso, or mineral wool, in the right thicknesses. 1x or sometimes 2x 4 boards, or furring strips as you’ll see them often on this site, attach to the wall through the insulation, through the sheathing, and into the stud to hold everything in place. This provides a mailing surface for the exterior cladding, while simultaneously providing an air gap, or capillary break, between the insulation and backside of the cladding.
If you google “the perfect wall” and Dr. Joe Lstuberick, you will start getting links that show the installation method. YouTube has a lot of resources that show this too, Matt Risinger’s channel is often the first that most people come across. There are many others once you get your Google fu calibrated on the right terminology.
Here’s one link to get you going:
https://www.buildingscience.com/documents/insights/bsi-001-the-perfect-wall
+1 Kyle very well said.
Walta
I don't understand the replies here because you are supposed to be able to install siding directly on the zip-r sheathing. According to Huber you can do that for siding that is not heavy enough to require nailing it all the way into the studs.
from the zip-r Installation Manual see page 8, attached image:
huberwood.com/uploads/documents/technical/literature/ZS_R-Sheathing_Installation_Manual-R3-12v21.pdf
richmass62,
I think the replies reflect that while Huber maybe happy for you to fasten the cladding directly to their sheathing, it might not be a good idea for other reasons than just the strength of the attachment.
- With the foam on the inside, the Zip layer will remain colder and more susceptible to moisture problems.
- Attaching cladding directly to sheathing that is already a bit vulnerable without providing a capillary break and a good drying path, is not a great idea.
The replies here are interesting. The product is designed to do everything yall are talking about and more. I would imagine if your sheer load is higher, your engineer will tell you whether or not you can install a thicker ZIP-R board.
As for nailbase panels, yes they are great. But then you are installed a SIP essentially if you use ZIP on the inside.
Replying to #2
re: shear strength - doing a "flash" w/polyurethane foam in the field (from a reputable contractor) on to the interior ZIP R surface (then "batt to the inside") will add shear strength
Replying to #8 - yes, in essence you are creating a type of Raycore "SIP" panel in the field
https://raycore.com/