More Product Guide
There’s a lot to like about the new category of peel-and-stick house wraps but working with them isn’t as simple as stapling a water-resistive-barrier (WRB) to the sheathing. This article is intended to offer helpful tips around self-adhered WRBs—from choosing the right product to installing it well, including the potential need for primer, getting a neat installation when rolling for adhesion, and integrating flashings.
Pros and cons
To create a fail-safe WRB, manufacturers have made steady innovations over the past few decades—from asphalt-saturated felt paper to fluid-applied membranes. Recently, adhered membranes have come onto the market promising both a water and an air barrier of uniform thickness that require no fasteners or seam-taping—attractive benefits. The disadvantages of adhered membranes include a labor-intensive process to avoid wrinkling the material, and sometimes the requirement to prime the sheathing for proper adhesion (which may compromise permeability). Some also require the use of special accessories and mastics at penetrations and terminations.
Manufacturers that make peel-and-stick WRBs
Henry Blueskin 1-2-3 Moisture Control System offers four types of self-adhered WRBs in 100-ft. rolls in five widths—from 4 in. to 48 in. Three membranes qualify as impermeable, while only Blueskin VP100 and VP160 are manufactured with 33 perms. When the material is applied at temperatures below 40ºF or on substrates such as gypsum board, masonry, concrete, and metal, it requires a primer (see below). The UV and climate exposure guarantee runs up to 150 days before cladding installation.
The manufacturer offers two impervious, self-adhering membranes—one for low-temperature applications and one with an aluminum shield for long-term UV exposure. Henry also touts the product’s “self-sealing” technology, which ensures its airtightness isn’t compromised by any penetrations.
Henry sells two primers to roll or spray on walls before applying the membrane. The company says…
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17 Comments
Good overview, Fernando. On a new Pretty Good House I designed, the builder wanted to try Rothoblaas' self-adhering membrane and they were very happy with it. They said it was easy to install and seemed very durable. The product is Traspir 150 Exterior Smart Membrane (807 SF per roll, 69 US perms, heavier duty than the competition at 150 grams per meter square).
The article is incorrect on Pro clima Solitex Mento 1000. It is not a self-adhered WRB. The pro clima self adhered offering is Solitex Adhero at about $1.02/ sq ft.
Not mentioned is Grace Env-s which is 15 perms and costs around $0.59/ sq ft.
Thanks, we'll fix it.
I appreciate the correction and have made it.
I wonder why I don't see more about Grace Env-s considering it's been out for a while and is from a major company.
Has anyone used Delta Stratus SA on roof or wall? If so, how was install? What were you adhering it to: plyboard, osb, tng ? Thanks
Anyone have feedback on hydrogap? I was considering using it on a double stud wall in climate zone 5. I only get 14” precip per year so I was thinking this might be a good solution instead of investing in a full rain screen. Any thoughts?
Matt,
I'd say a lot depends on the siding. Hydro gap gives y0u a better drainage plane than regular WRBs, but almost none of the other attributes of a rain-screen. If your wall assembly would be risky without good drying potential to the outside, and the siding doesn't aid that, then I think hydrogap might be a bad idea.
We were thinking of hardie plank siding. Where does this fall on the spectrum of drying potential? We are struggling with the concept of a rain screen. We live west of Salt Lake City, Utah and it is a high desert. No contractor I have spoken to has done a rain screen out here. I understand why it makes sense but just trying to understand if my local climate greatly reduces the risk. Trying to understand if this is a place to save money.
Matt,
Hardie isn't great that way, but your climate may well be enough to mitigate the risks. Hopefully someone more familiar with building there will chime in.
I think that concerns with mechanically fastened WRBs blowing off are a bit over...blown. If you follow (for example) Tyvek's instructions and use cap fasteners (I like 1 1/4" pnematic cap staples) ~16" oc (or closer if you like)... Tyvek's Commercial Wrap is quite hard to tear, and the instructions even include different fastener spacing recommendations for different design wind pressures. If you install rainscreen battens atop the WRB, it goes from "not gonna blow off" to "really not gonna blow off."
Self-adhered won't blow off either -- but is a far greater pain to install than mechanical, especially on a windy day. Sometimes the "look how easy it is" videos can be misleading... the time it took to set up that scaffold is rarely mentioned.
On the flip side, I think that the self-adhered crowd, to say nothing of the Zip-worshipping orgy, seriously understates the concern with reverse shingling. It's just totally glossed over. Having your WRB run *behind* your window flashing tape is far from ideal.
James,
Agree entirely.
Self adhered membranes sound like a great product for renovations, especially those with board sheathing, that would benefit from an exterior air-barrier. I'm not entirely convinced they bring much on new construction.
Perm Rating
The article notes Dan Kolbert's preference for the SIGA product given its high perm rating; but based on the values noted it seems the Majvest is at the low end. Is this accurate?
Thanks.
CT
CT,
It depends. High perms may not be of much benefit in a couple of situations. If your exterior sheathing is something like ZIP, I doubt the wall dries much better. And walls with reservoir cladding benefit from lower perm WRBs, which limit the amount of wetting that can occur due to inward solar vapour drive. 13 perms does seem pretty low though. Contrast that with regular Tyvek at 77, and Tyvek Commercial at 28.
Hi Malcom,
Thanks for clarifying. In my case, the self-adhered membrane will be part of of a double stud wall; dense pack cellulose, cdx ply sheathing, 1x rainscreen, shou-sugi ban cedar siding. Comparing and contrasting the Majvest vs. the Henry Blueskin, I'm wondering if that perm difference will matter in this assembly. Climate zone 6, Northern Michigan.
Cheers.
CT,
I'll admit it's not something I've thought a lot about, but CDX plywood can open up to 26 perms if it gets wet, so any WRB with less than that would inhibit drying in that situation. With cellulose in the wall, I can't see the sheathing getting anywhere near that damp though.
I'd be interested to hear what others think.
I don't think those numbers are right - I believe it is 16 perms dry and opens to about 24 wet.
Frankly I have a preference for SIGA largely because we have the biggest SIGA distributor right here in Portland, my discussion group co-host Steve Konstantino at Performance Building Supply.
It's also been a while since I've reviewed products (it's been a while since Fernando's article came out!) so a good reminder to take a fresh look. Thanks.
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