In the event of a severe storm, a durable roof may help protect against water intrusion at the most vulnerable area of a home. Whether caused by heavy thunderstorms, damaging winds or hurricanes, water intrusion through the roof can leave a homeowner out of their home for months or longer while waiting for insurance claims to be filed and repairs to be done.
Sealed roof decks built with integrated sheathing and tape can help achieve a quick rough dry-in to help interior crews start sooner and help protect interiors from water damage while a roof may be exposed before cladding. They also provide a continuous rigid air barrier by design, which reduces air leakage and can contribute energy efficiency benefits if the roof is built over a conditioned attic space.
For more than 20 years, the Insurance Institute for Business & Home Safety (IBHS) has extensively researched and tested what makes a strong roof. A result of this research is the Fortified Roof standard part of IBHS’s Fortified Home program, which promotes the use of a sealed roof deck as part of its nationally recognized standards for resilient building. Resilient construction is designing and building structures that can be easily re-inhabitable after disasters or other setbacks.
A sealed roof deck, such as the Zip System Roof Assembly, comprised of engineered wood panels with an integrated, water-resistive barrier and advanced acrylic tape, provides a secondary continuous water-resistive barrier on a roof deck that helps prevent water intrusion at panel seams. For example, ZIP System panels come with a built-in, weather-resistive underlayment, and when seams are sealed with ZIP System flashing tape, it creates a continuous water-resistive barrier that eliminates the need for additional felt or self-adhered membranes. In fact, ZIP System Roof Assembly is the first manufacturer-warranted roof sheathing system that meets the sealed roof deck standard for a Fortified Roof.
Additionally, builders can install the ZIP System peel and stick underlayment to help meet code requirements in areas prone to ice damage and wind-driven rain. The self-adhered, rubberized asphalt underlayment helps to further protect eaves, valleys or the entire roof, making projects eligible for a Leak Free Guarantee.
Traditional roof decks may be constructed with oriented strand board (OSB) or plywood panels as the structural sheathing layer. Next, 15lb-30lb felt (per local code) may be installed on top of the panels to repel water off of the wood substrate. Lastly, a roof covering, such as shingles, is attached.
There are four methods IBHS approves for installing a sealed roof deck to Fortified Roof standards:
- Using tape and underlayment, which requires a certain tape and underlayment material applied directly to the roof deck.
- Applying a full layer of self-adhering membrane to the roof deck.
- Installing two layers of felt underlayment to the roof deck.
- Applying spray foam on the underside of the roof at every joint and seam.
Explore more about what IBHS is doing to create safer, more durable homes at DisasterSafety.org
