How do you attach exterior siding without disturbing the air barrier, on a passive home build?

Scott Bowker July 16, 2018, 11:07 p.m.

I'm using the "Zip system" of exterior cladding. Over this I plan to install 6" of iso foam, for additional insulation, and siding over the foam.

I'm unsure how to attach anything to the "Zip system", without penetrating the airtight barrier.



Responses (1)

Ecohome July 26, 2018, 7:57 a.m. Reply

Hi Scott,

The Zip system is an air barrier sheathing when the joints are taped as specified by the manufacturer. There should not be any notable air leakage from additional fasteners used to attach insulation that you need to worry about. A nail or screw driven into wooden sheathing will pretty much fill its own hole.

In our 2015 demo house build we did put small pieces of FlexxBand tape on the sheathing where future nail holes would go, if that is the source of your concern I would apologize and tell you not to worry, that was a pretty high level of overkill on our part that was a suggestion from the manufacturer if we ‘really wanted to be sure’ as we had lots of it around. They were perhaps just responding to our concern to make the house as airtight as humanly possible. In hindsight that was a step we would not repeat, but rather save that roll for another project.