Thoughts on ZIP leak test video?
88Clayton
| Posted in General Questions on
Would love to hear some thoughts on the validity of this in the real world.
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They are conflating the roles of cladding, WRBs and sheathing. No one expects a WRB or a combined sheathing/WRB to withstand pressurized water. That's the role of the cladding.
Perhaps the way our building code here in BC describes wall assemblies helps explain this. It distinguishes between the primary-layer of protection (the cladding) and the secondary-layer (the WRB), and details their roles. The cladding should be constructed to stop all bulk-water intrusions. The WRB (in our case behind a rain-screen cavity) is there to stop moisture intrusion through capillary action, vapour-diffusion and as a back-up against flaws in the cladding layer that might allow small leaks.
Maybe not this part though?
"vapour-diffusion"
We're still building with a vapour-barrier on the inside of the wall so the WRB can not be a vapour-barrier.
If you have a cladding that can absorb a ton of water and then it gets hit with the sun, it will result in vapour making its way through the WRB (but then later drying out through that same WRB.)
Good points.