Cladding Confusion: EIFS Versus Stucco

Stucco or EIFS? The continuous insulation on this Hilton Suites answers the question.

As popular building materials, Exterior Insulation and Finish System (EIFS) and stucco often appear similar — if not the same. However, EIFS and stucco couldn’t be more different. Stucco, dating back to the Greeks and Romans, is composed of Portland cement, sand and water. EIFS, a lightweight cladding system, is comprised of a polystyrene insulation board secured to the exterior wall with an adhesive or mechanical fasteners, then reinforced with an acrylic plaster and fiberglass mesh on top, and finished with an acrylic and polymer coat that is both colorfast and crack-resistant.

Some of the most notable differences between the two can be detected in energy and thermal efficiency. Unlike stucco, EIFS serves as a continuous insulation system with no thermal bridging due to fasteners, which helps reduce building operation costs as well as air infiltration. EIFS also has the ability to achieve infinite design options with its wide array of aesthetic choices. EIFS can can look like nearly any material on the market; something stucco cannot achieve.

FAQs: Exterior Insulation and Finishing System (EIFS)

EIFS, continuous insulation

The Shops at 5th and Alton in Miami Beach, Florida show the commercial design potential of today's continuous insulation systems.

In the U.S., the International Building Code and ASTM International define Exterior Insulation and Finish System (EIFS) as a non-load-bearing, exterior wall cladding system that consists of the following: an insulation board attached either adhesively or mechanically, or both, to the substrate; an integrally reinforced base coat; and a textured protective finish coat. Prior to 2000, EIFS were barrier systems, meaning that the EIFS itself was the weather barrier. After 2000 the EIFS industry introduced the air/moisture barrier that resides behind the foam.

Today, EIFS is one of the most tested claddings in the construction industry. Research conducted by the Oak Ridge National Laboratory and supported by the Department of Energy, has validated that EIFS is the “best performing cladding” in relation to thermal and moisture control when compared to brick, stucco, and fiber cement siding. In addition EIFS is in full compliance with modern building codes, which emphasize energy conservation through the use of ci (continuous insulation) and a continuous air barrier. Their growing popularity is related to the desire for energy efficiency combined with design flexibility.