Replies

1. GBA Editor
   Kiley Jacques | Sep 21, 2021 03:41pm | #1

   Fine Homebuilding ambassador Nick Schiffer has this to say about Henry Blueskin VP100: Self-Stick WRB. And here are some thoughts from Martin Holladay on Grace Vycor: “Grace Vycor is a peel-and-stick product that is vapor-impermeable. You don't want to install Grace Vycor on the exterior side of your wall sheathing . . . You usually want a vapor-permeable material (for example, plastic housewrap like Tyvek or Typar) at this location.” Here is a link to an article on the topic: All About Water-Resistive Barriers.

1. 
   pvo88 | Sep 22, 2021 09:26am | #5

   Thanks for your input Kiley. I should add that I'll be adding exterior foam over the sheathing and WRB and pursuing "innie" door/window details. Based on arcticles I've read on here the permeance of the house wrap when under foam doesn't make much difference since the foam's permeance is so low. Is my understanding correct?

2. 
   tjanson | Sep 22, 2021 10:07am | #8

   Vycor ENV-S is actually vapor permeable, I think Martin is referring to "normal " Vycor Plus which is impermeable.

2. 
   woobagoobaa | Sep 21, 2021 04:05pm | #2

   IIRC Nick used VP100 on his Tuckerman project (South Boston). One of the reasons I ended up using it on my reno. Perm rating of 33 (?). That was gapped / aged board sheathing. so more of a reason to use the SA WRB.

3. 
   kyle_r | Sep 21, 2021 04:34pm | #3

   I’ve used Blue skin on a retrofit. Its a nice product. I found it easier to install vertically from the top of the wall down. I’m not sure I’d want to install it in cold weather. Think through how you would integrate windows and door flashing.

1. 
   pvo88 | Sep 22, 2021 09:28am | #6

   Thanks for the installation input.

4. Expert Member
   Akos | Sep 21, 2021 06:44pm | #4

   I've only worked with VP100 on walls and it is pretty easy to install. As Kyle suggest, the easiest is to install as vertical strips, similar to wall paper install. Overlap is the same in both horizontal or vertical joint. The adhesive is very sticky, had no problems adhering to lumber/OSB/CDX/gypsum sheathing. It also likes to stick to itself, it will tear if you try to unstick it, so the best is to peel the backing as you go.

   Unless your wall has very high water exposure, self adhered WRB is a bit overkill. For air sealing, all you need is a seams taped with a good quality tape (Zip, 3m 8067, Tescon) and install standard house wrap over it as your WRB.

1. 
   pvo88 | Sep 22, 2021 09:41am | #7

   Thanks for your input. My primary interest in a self adhering house wrap is from an air barrier perspective. My wall will feature the sheathing, WRB, 4" of exterior foam, a rain screen, and finally siding. "Innise" window/door details. I was intending on using a mechanically fastened house wrap but the following points started to make me look at alternatives:

   - The sheathing is OSB which has already been sided once and has an abundance of nail holes as potential leak paths.
   - OSB has proven to be a leaky material based on articles I've read on this site.
   - The amount of detailing work that goes in to properly sealing OSB and a mechanical house wrap seams quite high.

   If I already have to tape, caulk, and cap staple a mechanical house wrap I have been thinking a self stick wrap would save a lot of effort and reduce chances for errors.

   I'm totally open to suggestions however as I don't retrofit every day.

1. Expert Member
   Akos | Sep 22, 2021 09:28pm | #9

   I've mostly dealt with either lumber or t&g sheathing. Those have much bigger holes and are very hard to air seal without a fully adhered membrane.

   Nails holes and OSB do leak some air, but unless you are looking to certify to something like passive house, it won't be enough to matter. Your mechanically fastened house wrap held tight by the rigid insulation and strapping will also cover a lot of those holes.

   Taping sheathing and installing standard house wrap is much less work than fully adhered.

5. 
   p2018 | Dec 08, 2021 05:19pm | #10

   Vycor enV-s is awesome. Primer free and stickier than most of the others where you otherwise have to prime the seams--with enV-s you don't have to. I think you can pick it up at http://www.warehoos.com