Home Achieves Outstanding Energy Performance Rating

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IFC Home Featuring DuPont™ Tyvek® DrainWrap™ and DuPont™ FlexWrap™ NF Achieves Outstanding Energy Performance Rating


When Dave Joswiak decided to build a new home in Bloomer, Wisconsin, he was sure of two things: he wanted a sturdy house that would withstand severe weather and he wanted an energy-efficient home. What he didn’t know at that time was the important role DuPont™ Weatherization systems products would play in his dream home.

Searching for a Solution

After extensive research, Joswiak chose to build an insulated concrete form (ICF) house. ICF construction is compatible with virtually all home design styles and can be finished on the interior and exterior with standard materials. Different types of ICF forms for walls can be used, but basically, ICF construction involves placing reinforced concrete between two layers of expanded polystyrene insulation forms (EPS) or other insulating foam forms.

As Joswiak learned from his research, ICF houses easily survive high-force winds and even withstand earthquakes, when properly reinforced. They feature a more even, consistent temperature for increased comfort and lower utility bills, and they are typically quieter than other houses because much less sound gets through an ICF wall compared to an ordinary wood or metal frame wall.

Turning a Dream into Reality

Serving as his own general contractor, Joswiak sought out the advice of Randy Fenske, Senior Certified DuPont™ Tyvek® Specialist at Wausau Supply, and Dave Hepfler, a local Focus on Energy Consultant, before finalizing plans for his 2,351-square-foot ICF ranch-style home.

“I was interested in any recommendations that Randy and Dave could offer to help me build the most energy-efficient house possible,” said Joswiak.

Fenske, who has been selling building materials for 10 years, reviewed Joswiak’s plans and recommended that he use DuPont™ Tyvek® DrainWrap™ as the weather barrier and DuPont™ FlexWrap™ NF as the flashing material for the windows and doors.

“Based on Randy’s recommendation and discussions with Dave, I was convinced that DuPont™ Tyvek® DrainWrap™ would be the best choice as the weather-resistant barrier behind the engineered wood lap siding I planned to install,” said Joswiak.

“As for the FlexWrap™ NF, I didn’t even know this type of product existed, so I hadn’t planned on using anything,” explained Joswiak. “But after seeing the many benefits this flashing product delivers, I knew it was the right choice for my new house.”

Assistance from these two experts didn’t end there. Fenske visited the worksite several times to help assure that installation of the DuPont™ Tyvek® DrainWrap™ and DuPont™ FlexWrap™ NF was done correctly. Hepfler provided ongoing advice to help Joswiak in his efforts to meet the requirements of the new Focus on Energy program, which went into effect in January 2011—just 7 months before construction on this house began.

A Look at the DuPont™ Weatherization System Products Used

DuPont™ Tyvek® DrainWrap™ is engineered with vertical grooves on the surface to help channel bulk water out of the wall system, while allowing water vapor to pass through the moisture barrier, helping to promote drying in wall systems. Its unique nonwoven fiber structure helps stop air movement through the walls, helping to improve a home’s energy-efficiency.

DuPont™ Tyvek® DrainWrap™ is the product of choice when enhanced drainage is desired behind claddings such as primed wood, fiber cement siding and foam board applied over flat substrates.

A high-performance, self-adhered flashing made with DuPont™ Tyvek® and a 100% butyl-based adhesive layer, DuPont™ FlexWrap™ NF is wrapped into the rough opening before the window or door is installed, and adheres to the Tyvek® DrainWrap® making a continuous weather barrier possible. It’s especially effective for protecting the vulnerable bottom corners of sills where water damage is most likely to occur. This flashing also efficiently conforms around round-top and custom-shaped windows in one seamless step.

Rating the New House

The Focus on Energy New Homes™ Program connects Wisconsin builders with leading energy experts to construct new homes that are more energy efficient than other homes merely built to code. In December 2011, just a few weeks after Joswiak moved into his new home, Hepfler conducted a series of tests as part of the Focus on Energy New Homes™ Program Energy Certification process.

For a home to be certified, it must be at least 10 percent more energy efficient than the same home if built to current uniform dwelling code. Efficiency is based on total MMBtu consumption as calculated by REM/Rate. Joswiak’s new home performed exceptionally well and readily achieved this goal.

Additionally, a home has to achieve an air tightness standard, using a blower door test. Building air-tightness must be equal to, or less than 0.20 cfm (cubic feet per minute) per square foot of building shell area when the home is depressurized to minus 50 pascals. Hepfler measured whole house infiltration of the Joswiak home to be less than half of the required value for a house of this size.

The Joswiak home easily gained the desired certification.

The use of DuPont™ Tyvek® DrainWrap™ and DuPont™ FlexWrap™ NF played an important role, in conjunction with the ICF construction, in achieving this low air infiltration rate and will help protect Joswiak’s home against air infiltration and bulk water intrusion for years to come.

“We have a saying in this business,” explained Hepfler. “Build them tight, be sure to ventilate them right, use combustion safe heating systems and plan to manage moisture properly.” According to Hepfler, this house is a great example of putting this into action. And, DuPont™ Tyvek® DrainWrap™ and DuPont™ FlexWrap™ NF played a key role.

DuPont™ Tyvek® Weatherization Systems Products Used on this Project:

  • DuPont™ Tyvek® DrainWrap™
  • DuPont™ FlexWrap™ NF
  • DuPont™ Tyvek® Tape
  • DuPont™ Flashing Tape