Both stucco and traditional siding insulate your home and protect it from weather-related damage. Where you live often determines which cladding you are most familiar with, as each material’s popularity is largely determined by the climate and architectural style of a region. The preferred exterior finish for Mediterranean-style homes, stucco performs best in hot, dry climates. Stucco is a type of plaster or cement that is adhered to a wall surface via a binder that adds insulating abilities. The porous nature of stucco allows moderate amounts of moisture to pass through it without reaching the exterior walls of a home. However, stucco can only absorb so much water. In areas where heavy rainfall is common, it may not be the best cladding option for wood homes, as water is more likely to seep through the stucco and into the exterior walls.
Traditional or Portland cement stucco is typically applied to a surface in three layers—a scratch coat, a base coat, and a colored or finish coat. The first layer can be applied directly to the wall if the surface is concrete or masonry. If the wall is another material or if it has been painted, metal lath must be installed over the surface before the initial layer of stucco can be applied. Once the stucco dries, the process of applying the stucco and allowing it to set is repeated.
EIFS, sometimes referred to as synthetic stucco, usually consists of a layer of polystyrene insulation board covered with one colored or finish layer of stucco. The first layer of EIFS is glued and/or mechanically fastened to the exterior wall surface. While Portland cement stucco is most commonly installed on homes with masonry or concrete wall systems, EIFS is the more popular choice for homes with wood framing.
EIFS is easier and less time-consuming to install than traditional stucco, and it is less susceptible to fading and cracking. EIFS also provides significantly better insulation than traditional stucco and other cladding materials, such as brick. Although early versions of EIFS did not protect homes against moisture damage as effectively as Portland cement stucco, today’s EIFS is able to repel moisture at a level comparable to that of traditional stucco.
Stucco can develop cracks for a variety of reasons, including climate extremes and foundation settling. A crack can usually be sealed and covered with new stucco, but the texture of stucco makes it difficult to fill cracks seamlessly. Also, natural fading over time frequently results in a repaired section of stucco that is a slightly different color than the rest of the house. As cracking can indicate a structural problem, such as a shifting foundation, it is important to rectify the source of a crack, not just the crack itself, to keep your home protected from moisture damage.