Sheathing, Gaskets and Barriers Oh My!

By Megan Kramer, Performance Homes Consultant

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There are many products to consider when air sealing your new home. Like so many things, it is great to have choices, but it can also be overwhelming. I have put together a list of resource I found most helpful.

I always enjoy reading what Bruce Williams and his team at Zero Energy Project have to say. This is a fantastic overview of how to "Super-Seal the Building Envelope."

This video provides insight on the entire wall assembly and includes a Zip-Sheathing system. Hammer and Hand is a leading builder in Portland and Seattle. They build  Passive and Net Zero Homes.

One of the more common products being used on high efficiency new homes is the Zip-System. This is a system of sheathing and tape. They have a variety of products for different applications. This product was showcased on “This Old House.” 

In addition to the Z-System and other sheathing products, there are many ways to deal with penetrations in the building shell and leakage between framing members. These range from simple pipe gaskets, to framing gaskets and products like this one from the makers of great stuff - a leader in spray foam technology. 

Many of these options are tried and true being used across the globe with proven time-tested results. However, in the constant search to make air sealing less time consuming and more effective comes innovation.

There is a new product on the scene that is getting a lot of attention. It is just as controversial as AeroSeal for duct sealing when it first came out. This product is AeroBarrier. It involves using a blower door to depressurize the home to force tiny air sealing particles into all of the air leakage pathways. 

This product is extremely controversial from what I have read. Reactions to this product range from calls of #greenwashing and #epicfail to very positive first-hand accounts of success with very low ACH numbers, Here are some take-aways from what I have read:

  • Seals cracks up to 5/8th inch and will be most effective after all major items on the thermal bypass checklist have been addressed.

  • Essentially making a tight home tighter without a lot of time and labor.

  • Convenient and time-saving - but that does come at a cost.

  • Lack of transparency surrounding the chemical make-up of the product, but it is a GREEN Guard Gold Certified sealant.

So, it may not be the silver bullet the manufacture claims but may be a good product to keep in your quiver. You can read many industry experts debating this product on Green Building Advisor and LinkedIn. I am excited to hear more as AeroBarrier gains traction in the market.

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On the opposite end of the spectrum in terms of labor and speed, this DIY homebuilder offers an incredibly detailed account of his Passive House project including air sealing details. He also provides great insight into decision making and the turbulent process of working with subcontractors. Check out Kimchi and Kraut for some great tips!