REDUCING AIR LEAKAGE
One of the biggest obstacles to achieving superior energy-efficiency is air leakage. Air leakage is the unintended movement of air into or out of a building enclosure. This is caused when the materials that comprise a building’s air-barrier system are ineffective.
WHY ZIP SYSTEM?
By simply taping the ZIP System panel seams with ZIP System tape, ZIP System wall sheathing effectively seals the wall system, decreasing unwanted air leakage into and out of the home. ZIP System panels are structural PS-2 rated panels with permanently integrated protective barriers colored green for the wall and red for the roof. ZIP System products provide a durable assembly which is engineered to withstand the demands of the job site and to provide long term performance within the building structure. To prove the superior bond between ZIP System wall and roof panels and their protective barrier, we conduct extreme tests.
PS1 Overlay Bond Durability Test
In this test, we boil ZIP System panel specimens for four hours and then place them in an oven for 20 hours. The samples are then subjected to another four hour boiling followed by an attempt to pull the overlay off of the panel. Even after this extreme cycling of heat and moisture loading, the overlay cannot be separated from the underlying panel.
Freeze-Thaw Test
Assembled samples (panel sections joined with tape) are subjected to ten freeze-thaw cycles. Each cycle consists of eight hours drying at high heat, eight hours submersion in water, and then sixteen more hours of exposure to sub-zero temperatures. After the testing cycles are completed, samples are reviewed under magnification. ZIP System panels and tape were unaffected by this extreme temperature variation and showed no signs of cracking or delaminating or any other characteristic would affect performance as a water-resistive barrier.
The technology behind ZIP System sheathing helps provide one of the most comprehensive air barrier systems available—significantly reducing heating and cooling costs, improving a building's durability and creating a healthier indoor environment. In fact, compared to traditional housewrap, ZIP System reduces air leakage by 99%.
BUILD TIGHT, VENTILATE RIGHT
The building industry is abuzz right now over how tight is too tight when building a home. Can a tight envelope have a negative impact on moisture management or air quality in the home?
Some believe that a fair amount of 'accidental' air leakage is good for a home as it allows for a building to breathe. Unfortunately, this accidental air is uncontrollable and normally of poor quality because of its origin into the building—crawlspaces, attics, garages, etc.
Well-respected building science organizations such as ABAA (Air Barrier Association of America) and ASHRAE (American Society of Heating Refrigerating and Air-Conditioning Engineers) recommend that homes should be built as tightly as possible but with proper ventilation.
The message is clear:
BUILD TIGHT, VENTILATE RIGHT
THE BENEFITS OF REDUCED AIR LEAKAGE:
Preventing the loss of conditioned air - The United States Department of Energy reports that over 30 – 40 percent of the cost of heating and cooling a home is lost to uncontrolled air leakage. This can hamper the performance of other building systems such as insulation and HVAC. Proper air sealing helps reduce uncomfortable temperature fluctuations and often allows for smaller, more efficient HVAC equipment.
Lower utility bills - Maintaining conditioned air means less energy is needed to recondition the air. Less energy means lower utility bills. And since all building systems must perform well together to optimize the energy efficiency of a home, the savings can add up.
Moisture - Wherever air moves, water vapor can follow. Proper air sealing reduces the risk of water vapor moving into the wall system where prolonged exposure can result in moisture issues such as wood rotting and mold, which can cause expensive structural or health problems.
Indoor air quality - Air barrier systems help keep out pollutants such as suspended particulates, dust, insects, odors and more.
KEEPING UP TO CODE
The energy codes are changing faster than ever so adhering to code requirements is critical when building. ZIP System wall sheathing has been designed to meet the growingly stringent building code requirements:
- Current International Residential Codes (IRC) include the requirement of an air barrier to prevent air leakage through the building envelope (IECC Section 202).
- Compared to 2009 when 7 air changes per hour (ACH) were acceptable in any climate, in 2012, this number must be decreased to 3 or 5 air changes per hour, depending on the climate zone. A 'blower door test' which measures ACH will also become mandatory to verify code compliance.
- In order to meet EnergyStar certification on a new home, builders must prove that complete air barrier systems are in place throughout the house.
AN AIRTIGHT ARGUMENT FOR ZIP SYSTEM SHEATHING
Independent testing labs have demonstrated the difference in air leakage between ZIP System wall sheathing and traditional housewrap through standard air barrier assembly testing.
The results are clear. ZIP System wall sheathing outperformed traditional housewrap—proving the superiority of a ZIP System air barrier.