Spray Polyurethane Foam Has Structure-strengthening and Energy-efficiency Capabilities

A high-performance building material, spray polyurethane foam (SPF) is widely used as an effective, lasting roofing solution. With positive benefits, including versatility, thermal insulation, resistance to inclement weather cycling and storms, strengthening of the building envelope, long life span and durability, spray foam has enjoyed increased use among builders and roofing contractors alike.

A roof’s primary purpose is to protect the structure underneath it. As a roofing material, closed-cell SPF acts as a protective roofing mechanism and a thermal insulator. The lightweight material is ideal as a roofing solution when:

 As a roofing material, closed-cell SPF acts as a protective roofing mechanism and a thermal insulator.

As a roofing material, closed-cell SPF acts as a protective roofing mechanism and a thermal insulator.

  • the roof substrate has many penetrations.
  • the roof deck is an unusual shape or configuration.
  • the roof is being applied to a structure located in a severe-weather environment.
  • a lightweight option is needed.
  • a slope application is preferred to provide extra drainage capabilities.
  • keeping the existing roof cover is desired.

STRENGTH AND DURABILITY

SPF is considered a highly durable building material. The physical properties of the foam change little with time, accounting for a life span up to 30 years with regular care and maintenance. SPF roofing systems also strengthen the roof in multiple ways. Roofing spray foams possess a compressive strength of 40 to more than 60 pounds per inch. Spray foam’s adhesion strengthening capabilities are key, especially in locations where severe weather cycling, storms, wind, hail and other conditions are prevalent and commonly cause structure damage. Coastal and hurricane-prone regions are prime examples.

When applied to the interior side of a roof, closed-cell SPF can increase a building’s resistance to wind uplift during severe storms. When SPF is applied to built-up roofing and metal substrates, it increases resistance to wind uplift even further. A study conducted by the University of Florida, Gainesville, in 2007 found that applying closed-cell spray foam under a roof deck provides up to three times the resistance to wind uplift for wood roof sheathing panels when compared to a conventionally fastened roof.

Spray foam is a good solution for unusual configurations and areas with many penetrations.

Spray foam is a good solution for unusual configurations and areas with many penetrations.

Spray foam also is resistant to progressive peeling failure. Caused by wind, peeling happens at the roof’s edges when wind pulls flashings and copings away from their installed positions. Peeling looks like a tin can after it has been cut around the perimeter. When this happens, a chain reaction may occur and lead to catastrophic building failure. After the roof membrane, panels or tiles pull away, the board-stock insulation is exposed, often with less resistance to the lateral and uplift wind forces. Then the sheathing below and the substructure are subject to movement and wind or water damage, potentially leaving the entire building interior underneath open and vulnerable. SPF roofing is continuous, so it provides a water-resistant layer that is well adhered to the substrate.

When the Gaithersburg, Md.-based National Institute of Standards and Technology examined roofs following Hurricane Katrina, it found buildings with spray-foam roofs performed rather well without blow-off of the SPF or damage to flashings. The 2006 “Performance of Physical Structures in Hurricane Katrina and Hurricane Rita: A Reconnaissance Report” found that only one of the examined SPF roofs incurred notable damage, and that damage was confined to only 1 percent of the total roof system. The report concluded spray foam kept the roofs intact, prevented moisture from entering the buildings, and protected the structures from hail and debris.

Hurricane Katrina played a significant role in one of the largest reroofing projects ever on one of the largest metal-framed domed structures in the world: the Superdome in New Orleans. Katrina destroyed the dome’s second roof; the structure’s original roof was constructed with polyisocyanurate foam covered with a fluid-applied elastomeric coating but was replaced in 1989 with a single-ply EPDM roofing system. After the damages suffered during Katrina, the EPDM roof system was replaced with a spray foam roof system.

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Design and Construction Leaders Commit to Resilience

Tuesday, for the first time, leaders of America’s design and construction industry, along with building owners and operators, have agreed to promote resilience in contemporary planning, building materials, design, construction and operational techniques to help make the nation’s aging infrastructure more safe and secure.

CEOs of almost 24 leading design and construction industry associations, with more than 700,000 members generating almost $1 trillion in GDP, used the occasion of “Building Safety Month” to issue a joint statement on resilience. The statement was unveiled at a press conference at the National Building Museum, where a new major exhibition titled Designing for Disaster presents design and building solutions for disaster mitigation.

“We recognize that natural and manmade hazards pose an increasing threat to the safety of the public and the vitality of our nation,” reads the statement, in part. “We further recognize that contemporary planning, building materials, design, construction and operational techniques can make our communities more resilient to these threats.”

The CEOs committed their design and construction sector organizations to significantly improve the resilience of the nation’s entire built environment through research into new materials, construction procedures, and other methods to improve the standard of practice. Among other things, they also committed the industry to educating itself through continuous learning; to advocating for effective land use policies; to responding to disasters alongside first responders; and to planning for future events, with a strategy for fast recovery.

“By reaching out across the design and construction industry spectrum, the alliance could play a significant role in addressing major national imperatives as we design, plan, and build the future,” says ASLA Executive Vice President and CEO Nancy C. Somerville, Hon. ASLA, Hon. AIA. “Resilience is at the heart of what landscape architects do. I applaud our partners and look forward to working with them for the common good.”

In addition to the American Society of Landscape Architects, here is a list of organizations signing onto the joint statement on resilience:

    American Council of Engineering Companies
    American Institute of Architects
    American Planning Association
    American Society of Civil Engineers
    American Society of Interior Designers
    American Society of Landscape Architects
    American Society of Plumbing Engineers
    ASHRAE
    Associated Builders and Contractors
    Associated General Contractors of America
    Building Owners and Managers Association
    International Code Council
    International Interior Design Association
    Lean Construction Institute
    National Association of Home Builders
    National Institute of Building Sciences International Facility Management Association
    National Society of Professional Engineers
    Royal Institute of Chartered Surveyors
    Urban Land Institute
    U.S. Green Building Council

IBHS and FEMA Prepare Homes and Businesses for Natural Disasters

The Insurance Institute for Business & Home Safety (IBHS) recently joined with the Federal Emergency Management Agency (FEMA) in the first National Prepare-A-Thon, which was designed to help home and business owners become better prepared for natural disasters.

“Research shows that communities, families and individuals who prepare in advance for possible disasters are better able to recover from them and adapt to new or changing conditions,” says Julie Rochman, IBHS president and CEO. “Communities around the country [held] Prepare-A-Thon events April 30. The time to act is now before disasters threaten. These events are perfect opportunities to learn how to make your home and business safer and stronger in the face of disasters.”

The first step in preparing for a disaster is knowing what risks you face. IBHS provides an interactive risk map on its website to help you identify your region’s risks by entering your ZIP Code.

“A critical part of preparedness is making sure your home or business is disaster-resistant. Strengthening your building will make it more likely it will be there when you return after a disaster. A stronger, safer building will sustain less damage, making your community more resilient and requiring less federal and state aid to recover,” states Rochman.

IBHS provides a wealth of information for home and business owners about how to protect your home and business against damage from tornadoes, wildfires, floods and hurricanes.