Replies

1. GBA Editor
   Martin Holladay | Oct 23, 2017 09:38am | #1

   Steve,
   As far as I know, Agepan acts as sheathing (while also providing R-value). However, I don't think that Agepan is an approved water-resistive barrier (WRB).

   Building codes in the U.S. require, and building experts recommend, that every wall have a WRB. Tyvek will work fine.

   Almost all housewraps (including Tyvek) are vapor-permeable. A layer of housewrap will not trap moisture.

   All of this said, I urge you to follow the installation instructions provided by Agepan, as long as those instructions are consistent with U.S. building codes.

   Here is a link to an article with more information: All About Water-Resistive Barriers.

2. 
   sbabcock61 | Oct 23, 2017 10:08am | #2

   Thanks for the replay and Link

   The AgePan site has little information regarding WRB. on top of their product

   Typically Ontario building code requires a WRB which is why we went this route and most building inspectors want to see it

3. Expert Member
   Dana Dorsett | Oct 23, 2017 10:47am | #3

   According to their hype:

   "Agepan is water-resistant throughout, meaning that with the use of a
   rainscreen, no additional water-resistant barrier is needed on the exterior"

   "Agepan also differs from many other products that
   perform just one function; it can provide a thermal break,
   an integrated weather-resistive barrier (including air
   barrier), and a base for installation of a rainscreen and
   cladding all in one."

   
4. 
   sbabcock61 | Oct 23, 2017 11:24am | #4

   I guess things bring me back to #2 of my original question - any problem with leaving the Tyvek on top of the AgePan ?

5. Expert Member
   MALCOLM TAYLOR | Oct 23, 2017 11:26am | #5

   I've seen it used in Scotland with open-joint siding and no additional WRB. Not something I'd be comfortable doing, but evidently architects there are.

6. Expert Member
   MALCOLM TAYLOR | Oct 23, 2017 11:41am | #6

   Steve,
   No problem and a definite benefit. The Tyvek will allow you to use conventional lapped flashing at openings and changes in siding materials, rather than relying on tape at those joints.

7. GBA Editor
   Martin Holladay | Oct 23, 2017 01:23pm | #7

   Steve,
   Building inspectors may want to see a WRB. I'm not sure whether Agepan has been tested by the ICC Evaluation Service, a necessary step in North America (usually) to have a product certified as a WRB.

   So I suggest that you go with the Tyvek.