“In this series, we will share information we've gathered on different exterior insulation products, installation methods, and insights from industry professionals that may help your decision process—starting with ZIP System™ R-sheathing."
If you are in some way connected to the building industry, it probably feels like the Washington State Energy Code is a continuous topic of conversation. We at Dunn Lumber can certainly relate. That's why we decided to create our Exterior Insulation Series. We've found that almost everyone is trying to figure out the path forward. In this series we will share information we've gathered on different exterior insulation products, installation methods, and insights from industry professionals that may help your decision process. In this article we are focusing on the ZIP System™ R-sheathing product from Huber Engineered Woods.
Product information and stated benefits
ZIP System™ R-sheathing is marketed as an all-in-one structural panel with built-in exterior insulation.
The product features polyisocyanurate rigid exterior insulation on the back of the structural panel that reduces heat transfer and helps keep homes more comfortable.
ZIP System™ R-sheathing has a resin-impregnated, water-resistive barrier manufactured onto the structural panel that acts as a housewrap, sheds water to the exterior, and is backed by a 180-day exposure guarantee.
When seams are properly sealed with the advanced acrylic ZIP System™ tape or ZIP System™ liquid flash, a continuous air and water barrier is formed that helps manage water and reduces air leaks.
ZIP System™ R-sheathing comes in four-by-eight, four-by-nine and four-by-ten sizes (four-by-nine and four-by-ten have extended lead times), as well as four different R-values and foam thicknesses:
- ½" foam is R-3
- 1" foam is R-6
- 1 ½" foam is R-9
- 2" foam is R-12
Storage recommendations
On the jobsite, the product should be covered with a tarp (loosely) to promote air circulation.
Stack the product on a minimum of three supports to keep it off the ground and do not stack the product more than three units high.
Before tarping, cut slits in the factory-applied packaging to prevent the accumulation of condensation.
Installation details to be aware of
As with most products, ZIP System™ R-sheathing requires attention to detail and weather conditions for a proper and warranted installation.
It is recommended to NOT apply a fluid-applied WRB or self-adhered WRB over the entire ZIP System™ wall assembly.
Before taping seams, all panel surfaces should be dry and free of dirt and sawdust.
When rolling tape with the J-roller, be sure to remove any wrinkles. If unsuccessful, replace the tape with a new piece.
ZIP System™ flashing tape and stretch tape are pressure sensitive tapes that must be rolled with a rubber-faced roller in order to achieve maximum bond to the panel.
Structural straps, ties, and connectors should be attached directly to the wall framing under the ZIP System™ R-Sheathing.
When butting ZIP System™ R-sheathing into a masonry wall (i.e., chimney, etc.) leave a ½" gap and fill with backer rod, then use ZIP System™ liquid flash to bridge the joint.
Other things to consider
Scratches and other damage to the resin coating on the OSB can let moisture soak through the sheathing over time. Consider installing a basic housewrap as an extra layer of protection. If you choose to add this extra layer of protection, research the fastening requirements for your cladding materials in case you need to identify framing stud locations before you cover up the ZIP System™ R-Sheathing.
Adding a layer of exterior insulation is going to be a change from the usual routine for many builders and remodelers. In addition to doing your homework on how the wall assembly will be impacted from a building science standpoint, pay close attention to traditional wall penetrations, as well as window and door openings. Additional product knowledge and/or hands-on training is available for Zip System products. To schedule, please contact jimc@dunnlumber.com.
Explore more energy efficiency guidance
Exterior insulation is just one of the many ways you can ensure energy performance for your home. For more professional guidance on how to optimize your home’s efficiency, explore blog articles like Energy Retrofit Series: How to Balance Your Home’s Health and Efficiency and Green Building Innovation in New Home Construction.