Fr om New York’s iconic brownstones to Alaska’s wooden homesteads to the stuccoed exteriors of New Mexico, US architectural styles vary widely from state to state. The same is true for siding trends, which are influenced by aesthetic preferences and varying factors such as material pricing, labor costs and availability.
Data gathered by the United States Census Bureau indicates significant changes in siding preferences over time for newly constructed single-family homes. The data also highlights the substantial differences in substrate predilections by region.
For formulators of exterior architectural coatings, it’s important to understand these trends and how they will impact the performance expectations of end customers, so that they can adapt the characteristics of their formulations for the next generation of paints.
Changing exterior trends over 20 years
According to the US Census Bureau data, siding preferences for new single-family residential construction have changed drastically in the past 20 years (Figure 1). The popularity of wood exteriors, for instance, has gone down from 16 percent to 5 percent. Fiber cement, on the other hand, has grown in use from under 1 percent to 20 percent.
There was a less notable decrease in the use of vinyl siding, while the use of stucco increased slightly. Brick exteriors have remained more or less constant in their popularity.
“Fiber cement and stucco are driving the latest siding trends,” says Camilo Quiñones, Market Segment Manager of Architectural Coatings at BASF. “Fiber cement is fairly durable and competitive from a cost standpoint.”
These numbers are good news for exterior paint formulators overall, because the two materials with the most notable increases in popularity — fiber cement and stucco — are substrates that typically require paint on the original installation and repaint (as opposed to materials like brick and vinyl, which are not commonly painted over).
Regional siding differences
Besides factors like cost and performance, regional differences account for much of the variance in siding preferences across the US (Figure 2). When it comes to newly constructed homes, the Western and Southern US have been hugely influential on the statistics.
“In the last decade, the West and South have become the big areas of development for the United States,” Quiñones explains. “Of the 840,000 houses built in 2018, 53 percent were in the South, and 25 percent were in the West. The two regions combined account for more than three quarters of all the new single-family houses last year.”
A closer look at the regional siding preferences reveals a preference for stucco and fiber cement in the West, as well as brick, vinyl and stucco in the South.
“The trends are a combination of material preferences from the end-consumer, as well as the prevailing architectural style in the regions where new housing is built,” Quiñones says.
A 40-year inventory of siding materials
Though wood and other materials are declining in popularity, formulators can still gain some insight from a historical look at existing single-family residences.
A look at the last 40-years of census data on siding preferences provides an understanding of the existing houses and the distribution of substrates for exterior repaint (Figure 3). Data for this “40-year housing inventory” shows that preferences are more evenly distributed across substrates than what the latest annual snapshot would suggest. Brick, vinyl, and wood show equal prevalence with 22 percent, followed by stucco at 18 percent, others at 12 percent (e.g. concrete block, stone, aluminum siding and other types), and fiber cement at 4 percent.
“All siding types are still very well represented. Fiber cement is really something that has begun to develop in the past 10 years or so, which is why it’s not as well represented in terms of a 40-year-old inventory,” Quiñones explains. “Then you look at wood, which was a siding choice in only 5 percent of houses in 2018, but it still accounts for 22 percent of the houses that are still out there.”
Even where they clash with current trends, formulators will want to take note of the historical numbers, as many of these existing residences will need to be repainted at some point.
Formulators: What does it all mean?
Exterior paint formulators can act on all this data by considering the performance characteristics they want in their products.
“Given the latest preference for stucco and fiber cement, paints with good resistance to efflorescence and alkaline burn will become more relevant,” Quiñones says. “As cementitious materials become more important over time, those two properties will be very important.”
Efflorescence is the effect of salt migrating through a paint and crystallizing in the surface, while alkali burning refers to a loss of color and deterioration of the paint film when applied over fresh masonry, stucco, or another cementitious substrate.
To make sure your paint formulations excel at those properties, Quiñones recommends ACRONAL® EDGE 4247, an acrylic latex for exterior paint-and-primer-in-one — in other words, it combines the properties of a primer and topcoat. The product provides high performance in paints ranging from flat to semi-gloss.
“When you need high efflorescence resistance and alkaline burn resistance, ACRONAL EDGE 4247 is an outstanding choice,” he says.
That makes the product perfect for stucco and fiber cement, but it also works very well when applied to a wood substrate. That’s because ACRONAL EDGE 4247 is flexible enough to accommodate the quirks of wood exteriors.
“Wood is a fairly unstable substrate — as temperature and moisture changes throughout the seasons, the wood expands and contracts,” Quiñones explains. “The coating applied on top should be resilient enough to withstand the movement and prevent cracking.”
Then there are the universal performance requirements every exterior coating should have. Strong adhesion is important all around, because it ensures the paint will stay fixed to the substrate.
“You also want good resistance to water, especially while the film is still curing,” Quiñones says. “And dirt pickup resistance is important to make sure dirt, pollen or anything else floating in the air doesn’t stick to the side of the house.”
ACRONAL EDGE 4247 provides all of those characteristics to keep exterior coatings looking fresh and new for as long as possible.
Considering the variety of substrates used throughout the US — both in recent trends and the 40-year inventory — formulators will need to make sure their paint is versatile enough to work on any surface. The paint should accommodate the needs of wood, cementitious materials or whatever else is needed without compromising on the overall performance of the exterior coating.
Contact a BASF representative for help in formulating an exterior paint that does all that and more.