Creating Resiliency Through Material Choices

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In addition to site considerations, design and construction techniques, and code adherence, material choice is an important factor for producing resilient structures. Such choices can influence a home’s ability to minimize risks from natural occurrences, such as hurricanes, floods, earthquakes, fires, snow, and tornadoes. Certain risks vary by geographic location, necessitating different strategies and material choices to fortify exteriors. When building in wildland urban interfaces, clay tile, stucco, asphalt shingle roofs, and metal roofing are recommended because of each material’s strong fire rating, while prefinished products, such as vinyl siding, concrete siding, aluminum soffit, and aluminum gutters, are recommended to improve installation time and performance in cold weather climates.

The Home Innovation Research Labs, a subsidiary of the NAHB, produces an annual Builder Practices Survey, providing insights on building products and material usage for new-home construction, documenting the popularity of products and materials, based on a nationwide survey of builders. The research in the annual report, broken down regionally and by project type, includes several categories related to creating resilient structures, including roofing underlayment and materials, window and window glazing, exterior finishes, and door materials.

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Windows and Doors

Impact-resistant windows, which consist of impact-resistant glass surrounded by a heavy-duty frame, help guard against hurricane winds and debris penetration. According to the 2022 Builder Practices Survey, 8% of new construction homes in the U.S. used impact-resistant windows in 2021. The share has increased marginally from 5% in 2014, though is 2 percentage points below its peak market share of 9% in 2019.

Vinyl (54%) and wood (29%) were the most popular window material choices by builders on a national basis for new construction homes in 2021, according to the Home Innovation Research Labs. Aluminum, fiberglass, composite, and other materials all hold a market share of less than 8% for new construction homes on a national basis. While wood provides a traditional aesthetic appearance for homes, it requires more maintenance and upkeep than materials such as fiberglass and vinyl, both durable water-resistant materials. Fiberglass windows, while more expensive than vinyl, offer more durability against extreme weather. Steel, another material option for both windows and doors with a small market share, provides higher yield strength than materials such as aluminum and conducts heat and cold at one-fifth the rate of aluminum substrates.

Data from the annual Builder Practices Survey indicates nearly half of new construction homes built in 2021 used fiberglass or composite materials for exterior door systems. Steel (30%) and wood (21%) were other materials favored by builders for exterior doors in 2021. Fiberglass, in addition to being less expensive than wood, features a polyurethane foam core that insulates the door against extreme temperatures and is not susceptible to similar long-term maintenance issues and damage as steel and wood doors. Wood doors, though, with thick solid cores, are noncombustible and perform strongly against wildfires.

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Roofing

Durable roofs can provide protection against water intrusion in the case of a heavy storm as well as additional protection against fire spread if properly fortified. In addition to roofing material choices and systems, roofing underlayments serve as a secondary drainage plan, providing a flashing to direct water away from vulnerable places in the structure.

The use of asphalt felt roofing underlayment, the preferred method of roofing protection for many years, was used in 37% of new construction homes in 2021, according to the Home Innovation Research Labs’ annual Builder Practices Survey. Innovations in the roofing underlayment segment, including synthetic roofing underlayments and self-adhered peel-and-stick roofing underlayments, provide greater protection and resilience against the elements. The use of self-adhered, peel-and-stick roofing underlayment creates a sealed roof deck and is considered the most resilient, according to the Home Innovation Research Labs. However, peel-and-stick underlayment was used in just 26% of single-family new construction homes in 2021, according to the survey. Synthetic roofing underlayment (used in 38% of new construction homes in 2021), while less resilient than peel-and-stick underlayment, is more durable and resistant to blowoff than traditional asphalt felt roofing underlayment, and has better resistance to tearing, moisture, and UV rays than traditional roofing felt.

According to the annual Builder Practices Survey, asphalt and single-ply roofing was used in 81% of new construction, single-family homes nationwide in 2021. Clay and concrete tile (10%), metal (8%), slate (1%), and wood (1%) accounted for other roofing material choices in new single-family homes in 2021. Clay tile, metal roofing, and certain asphalt shingles hold Class A ratings for fire-resistance and are noncombustible, ideal for use in areas prone to wildfires. Roofing materials such as cedar wood shake and shingles can ignite in the case of a fire, producing embers and presenting the risk of structure-to-structure fire spread.

Approximately 59% of builders used roof truss systems during single-family new construction builds in 2021, according to the annual Builder Practices Survey. Joe Flynn, the Minneapolis/St. Paul division president of David Weekley Homes, says elevating the roof system through the use of roof trusses with extended heels of at least 10 inches is important in cold weather climates to allow the roof system to remain the same temperature as the outside air and prevent the creation of ice dams on roofs and gutters.

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Exterior Siding

While brick and stone and fiber cement both held a 25% market share nationally for new construction homes built in 2021, according to the annual Builder Practices Survey, stucco (16% national share in 2021) is a more popular siding material choice in the Southeast, Mountain, and West regions. David Templeton, senior vice president of home building for Holt Homes, which operates in Oregon and Washington, says the builder favors the use of fiber cement due to its quality and durability in the cold and west climate in the Pacific Northwest.

Vinyl and polymer (15% national share) are also more regionally popular in the Mid-Atlantic, Northeast, and New England regions. Brick and stone holds a commanding market share for new single-family homes built in the Southwest region of the United States and carry strong fire-resistance. Vinyl and many natural wood products are more often either direct fuel sources or vulnerable to fire. Stucco, manufactured stone, such as fiber cement, and composite siding are also strong performers against fire.

In fire-prone areas, installing safety measures such as fire sprinklers can help reduce the spread of some types of fires. While prevalent in regions that are more prone to wildfires, fire sprinklers were installed in only 15% of single-family detached homes in 2021, according to survey data from the Home Innovation Research Labs.

At the world’s largest competition of bricklayers, robots fall short of the speed and precision that the trade requires. Adobe Stock/Halfpoint

Above-Grade Exterior Walls

Consistent with data from recent years, above-grade portions of most residential structures in 2021 were built primarily with structural wood framing, according to the Home Innovation Research Labs. Wood-framed houses can resist lateral loads imposed by hurricane-force winds and lower vulnerability to earthquake damage as well. Approximately 86% of new U.S. homes were constructed with above-grade wood-framed walls, while 13% features above-grade concrete and masonry walls. The share of homes using above-ground concrete walls has increased slightly from 10% in 2017, but the share has largely remained unchanged over the past few decades, according to the annual Builder Practices Survey.

Most concrete and masonry wall construction in the United States is concrete block, and the material is mainly used in Central and South Florida, where water, wind, and termites are plentiful, presenting risks to traditional wood structures. Outside of Florida, concrete is typically found in higher-end luxury homes rather than starter homes, according to the survey data. Concrete walls, typically more expensive than wood-frame walls, provide resistance and durability against wind and flooding forces during storms. Above-grade concrete also provides energy efficiency and savings, requiring less energy to heat and cool a building structure.

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