Anne Whitacre, I think you have those products reversed. The DensElement is more like an impregnated sheathing board. The Exoair has a cured coating on the top and we have observed that it pulls away easily from the sheathing whenever boards are cut.
When you consider that the original Canadian standard for air in/ex-filtration was a piece of 1/2 inch thick gypsum board taped to a vacuum chamber, the idea of using 5/8-inch glass fiber faced siliconized gypsum sheathing made sense.
I wrote a spec for sheathing/WRB on a project that used only DensGlas Gold and Henry Blue-Skin tape. During construction, it looked like Cub Scout headquarters, but it has worked. The tedious application of the Blueskin primer and generous application of tape at flashings and penetrations has been successful.
Further research revealed that a coat of acrylic masonry coating on the DensGlas worked very well as a primer for the SAM and provided an extra layer of confidence for the Owner. The drywall sub on the project shop-coated the sheathing and saved 2 weeks on the construction schedule - Big savings.
DensElement is an outgrowth of those projects and I find it effective and cost saving,
FYI: I was part of a focus group in 1987 st G-P Atlanta HQ before DensGlas was introduced. G-P followed the group’s recommendation and has a very successful product. I’m glad to see that USG and other manufacturers are catching on.
In February 2020 3rd party comparison testing was published highlighting water resistance performance differences between DensElement and Securock ExoAir 430.
USG sponsored a small portion of the research cost published in a White Paper. The document can be found at:
Or I can forward a copy if you email me. Glad to answer any questions about it.
Scott Sellers
USG - ssellers@usg.com
[I was asked to post this - Colin]
Colin, thank you for posting that!
DensElement Barrier System has been installed in over 500 projects across the United States and Canada since 2015.
Extensive testing has been run to validate the performance of DensElement Barrier System, all by third party accredited labs as summarized here:
https://www.buildgp.com/wp-content/uploads/2019/11/DensElement_Testing_Matrix_Digital.pdf
I would recommend to anyone who is comparing these two products to familiarize themselves with the white papers published by Georgia-Pacific including this most recent one:
https://www.buildgp.com/wp-content/uploads/2020/02/DensElement-WhitePaper-RainScreen.pdf
You will see that DensElement Barrier System exceeds performance requirements set forth in building codes even when penetrated by mechanical attachment of rainscreen subframe systems.
I am also available to offer answer questions or speak to testing of DensElement Barrier System directly: john.chamberlin@gapac.com
Have seen Steven Doggett present at my BEC. Very arrogant guy who makes up his own test methods and points out problems but never offers solutions.
USG funded the white paper, so of course it shows GPs product in a negative light
Since when are water-resistant barriers required to withstand hydrostatic pressure - prolonged or otherwise? Since when?
This “test” would be similar to testing awning fabric to support a 10 foot tall, 12 inch diameter concrete column point load. It is neither designed nor required to do such a thing. It is designed to support SOME load (snow, wind, etc.) but not a concrete column!
Absolutely ridiculous.
Wwater-resistant barriers are designed to RESIST incidental moisture that gets beyond the primary line of defense (i.e. the cladding) as a SECONDARY line of defense within an above-grade, exterior wall assembly. Think about that for a moment.
This is but another Spinal Tap selling tactic: “But, this goes to 11!” 10 is just fine.