Replies

1. Expert Member
   Malcolm Taylor|Apr 18, 2020 11:39pm|#1

   Mike,

   There is no reason to use two WRBs. Where you put it, over or under the foam depends on how you want to integrate it with openings, etc. Both places work fine.
   //m.etiketa4.com/article/where-does-the-housewrap-go

2. 
   Jon R|Apr 19, 2020 08:36pm|#2

   And even if you did use two, WRB is quite vapor permeable and so it wouldn't trap water vapor.

3. 
   Mike Taylor|Apr 20, 2020 03:52pm|#3

   Thanks, Malcolm and John. I've read 'where-does-the-housewrap-go' and my windows will be 'outies' so I'll put the WRB on the outside of the 3" EPS foam board. Any recommendations for WRB?

1. Expert Member
   Malcolm Taylor|Apr 20, 2020 07:00pm|#4

   Mike,

   I like Tyvek Commercial. It's a lot like regular Tyvek, but much harder to tear.

4. 
   Mike Taylor|Apr 20, 2020 08:44pm|#5

   Thanks. I would think that putting WRB on top of EPS foam is not easy and because it is only sandwiched every vertical 16", easier to damage before the Hardie Board panels are applied; so, I appreciate the Tyvek Commercial advice. A peel and stick product may make application easier. Is there such a product that adhers to EPS foam board?

1. Expert Member
   Malcolm Taylor|Apr 20, 2020 09:20pm|#6

   Mike,

   I've never used an adhered WRB. Looking at some of the manufacturer's installation video, two guys seem to have bit of trouble putting it on a mocked up wall in a shop. Maybe it's easier, or maybe it sticks to itself at every opportunity and is a nightmare.