Alternative for Three-Coat Stucco Rated Positively

An independent evaluation by IBACOS has attested that a substrate and textured acrylic finish system has the potential for improved labor savings, water resistance and durability over traditional three-coat stucco.

IBACOS is a housing innovation company that drives the research and development of new products and technologies to improve building quality and performance across the United States.

IBACOS conducted both in-field and off-site evaluations of LP® ArmorStrand® featuring Dryvit® TAFS® 3. IBACOS found that the system clearly has positive economic value compared to three-coat stucco. It meets all necessary durability requirements to combat (natural) elements.

Time and Motion Study vs. Three-Coat Stucco

The table below shows the tasks associated with each system installation and the approximate time it took to accomplish each task. These comparisons were based on a 12-foot-by-10-foot standard wall with a window assembly installed in the center of the wall. The analysis does not include any hydration cycling required for the proper application of traditional stucco scratch and brown coats, which would add time to the installation process.

“Three-coat stucco can take several weeks for installation, but the LP ArmorStrand system can be installed in just three to four days,” said David Josey, segment manager, Single Family New Construction (SFNC) – Siding, LP Building Products. “The system typically incurs lower material costs and has shorter cure times.”

Water Performance Analysis

A life-cycle load test per ASTM E233 criteria subjected the surface condition of the wall to 10 specific load weights. The test panel showed no visible signs of surface cracking, thus meeting the established criteria.
A water penetration test per ASTM E331 criteria attempted to draw water through any breaches of the wall surface to the framing under stress according to ASTM E72 guidelines, adapted with framing and window installation. The test sample showed no visible water penetration within the wall cavities, thus meeting the established criteria.

Energy Code Analysis

The system can be applied to meet the prescriptive requirements for continuous insulation in the IECC 2012 and 2015 across different climate zones. With proper use and installation of structural framing and wall cavity insulation, the LP substrate is acceptable in climate zones 1 through 5 – the majority of the United States. Additional development of the system is needed to meet IECC requirements for zones 6 through 8 (extremely cold climates).

Builder Prediction

The system helps address the labor shortage. “The system eliminates some equipment and laborers and the application was quicker than three-coat stucco. Stucco will be phased out over the next few years and replaced with this type of system,” predicted Vance Prestwood, co-owner of Plemmons & Prestwood Custom Construction, L.L.C. in Baldwin, Fla.

Substrate

LP ArmorStrand is a smooth, treated engineered wood strand product that comes in 4-feet-by-8-feet, 4-feet-by-9-feet and 4-feet-by-10-feet sizes. It replaces the normal OSB sheathing in the framing package, works and cuts like wood and requires no special tools.

The LP product is manufactured with a proprietary SmartGuard® process, which provides additional strength to the substrate and helps it resist moisture, fungal decay and termite damage. It is approved – by the APA® – The Engineered Wood Association – for single-wall construction over a code-approved water-resistive barrier.

Finish

The finish is applied to the LP product to achieve the desired aesthetics. TAFS 3 includes joint treatment, primer and a textured, integrally colored acrylic finish. With a virtually unlimited range of textures and color options, TAFS 3 can be customized to meet the homeowner’s taste.

“While many of the textures replicate stucco, special finishes are also available to provide the realistic look of granite, limestone and even brick. This design flexibility allows builders to offer many other high-demand exterior ‘looks’ beyond stucco when using the LP ArmorStrand featuring Dryvit TAFS 3 system,” said Tony Stall, vice president, business development, Dryvit Systems. “Best of all, they all are available from a single source and may be installed by a single subcontractor.”

The textured acrylic finishes can be created in virtually any color that complements a home using high-performance, UV-resistant pigments specially engineered for particularly bright or intense shades. These finishes are flexible and durable and resist cracking.

Product Warranties

The LP ArmorStrand substrate comes with a 5-/50-year transferrable limited warranty; see www.lparmorstrand.com for complete warranty details. Dryvit TAFS 3 comes with a 10-year materials limited warranty. Contact Dryvit at 800.556.7752 for more information and complete warranty details.

For more information about LP ArmorStrand featuring Dryvit TAFS 3, call toll-free 888.820.0325 or visit www.lparmorstrand.com.