Zip Sheathing and Rainscreens
Hi Folks, looking for some suggestions on to do a rain screen or not. We are using 5/4 stock Boral for window trim packs so I think I have the thickness there to go with a rain screen either in 6mm or 10mm, leaning 6mm to be sure. Has anyone used Mortairvent 6mm for Cedar shake installs ? Or is it best to just use Benj. Obdyke solution… they both appear to be a 3d mess material but Mortair has a thin screen attached. Shakes are pre dipped in 1 coat of stain from Maibec. Looks like builders in my area don’t use the rain screens very much for cedar shake installs as I have noticed, Is it worth doing to let air gap to dry the shakes, wouldn’t it open the door to insects, bees etc, nesting in this void ?
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I just did exactly this last year. Western Red cedar shingles, Mortairvent, Zip. I also heard from the local builders that nobody does rain screens since the shingles will hold up just fine for 10-15 years without it. But what about after that? Since this was for my own house I used the rain screen to keep me covered for more of a 25+ year install.
The bugs aren't an issue as the rain screen has a flap of mesh to cover the bottom that they can't get through. Theoretically a bug would have an easier time getting into any shingled house between the shingles at any point along the wall vs behind the shingle at the bottom of the rain screen, so not an issue.
If you happen to be in the PNW, I have a leftover roll of Mortairvent for you if you want it.
Hi @RobRMR and @andy_. This is an old post so I'm not sure if you'll see this, but I'm hoping someone will. How was you experience with using Mortairvent? I might use it in a similar situation.
I'm and architect working in Detroit. I spec'ed Slicker to be used behind wood siding. The GC is asking if he can use MortairVent instead because it's in stock locally and he's familiar with it. I want to make sure that I'm not giving the ok to use something that wont work as well in this situation.
The felt screen layer seems like its only useful if it's being used behind masonry or stucco. If that layer it lays against the back of wood siding, it seems like it would not create a capillary break at the back of the siding. That would make it less effective at drying the wood than something like Slicker, which doesn't have that layer.
In case they don't respond, I'll say that Mortairvent is in all ways that I'm aware of equivalent to Slicker Classic. The scrim layer seems to help spread out the load so it's not as compressible when nailing on cladding. Capillary action only occurs from larger pores to smaller pores; the scrim pores are large and the spun-bonded polyolefin gaps are even larger so there is no real concern with wicking.
Thanks Michael
Randomly enough after a while of not the Q&A, I did just stumble back onto this thread and found that I had already answered the original question!
Michael has given a better worded and more detailed follow up than I'd have come up with, but yeah...Mortairvent is a fine equivalent to Slicker. I've now used it on a couple other projects and it's been a breeze to work with.