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Synthetic Stucco (EIFS) Problems

Synthetic Stucco (EIFS) Problems
Synthetic stucco is one of the widely used wall coatings. Though it is claimed to be advantageous in various ways, it may develop certain problems. Read on...
Sonia Nair
Sailors Home Historic Building Exterior
Stucco is a popular type of finishing plaster that is usually used for exterior surfaces of buildings. Besides being used as a wall covering, stucco is also used for molding architectural decorations. The history of human use of stucco has been traced back to ancient Romans and Greeks. At that time, stucco was made with sand and lime water. With the invention of Portland cement during middle of the nineteenth century, the nature of stucco too changed. Even this cement was added as an ingredient for making stucco. Apart from this traditional form of stucco, now we have a latest version called synthetic stucco. As compared to the traditional form, synthetic stucco is said to be advantageous in various ways. However, it is not free of problems.

More About Synthetic Stucco

This type of stucco was initially used in Europe, as a repairing material for walls of buildings that were damaged in the World War II. Later, this stucco was widely accepted in Europe as a material for repairing walls made of concrete, bricks and stone. Synthetic stucco got popular in other regions like the Americas, during the last decades of the twentieth century. They started using it as an exterior finish for both commercial buildings as well as residences, especially those with wooden frames. It was considered an ideal choice for exterior finish. Apart from being durable and long-lasting, this type of stucco is also said to have less maintenance. It has insulating properties and is also adaptable to different architectural styles. However, with time, the defects of this stucco were identified.

Synthetic stucco is not like the traditional one that is a mixture of cement, lime water and sand. While, the traditional stucco is applied as three coats of the cement mixture over a stucco lath, synthetic ones have multiple layers. Otherwise known as Exterior Insulation Finishing System (EIFS), synthetic stucco is applied over a sheathing that is attached to the substrate (either wooden, brick, concrete or stone surface of the exterior wall). The inner layer of the stucco is a foam insulation board that is applied on the sheathing with the help of adhesives. The inner layer is followed by a coat of polymer and cement mix. This layer is reinforced with a fiberglass mesh. This forms the base coat on which the top coat is sprayed or applied with trowel. This stucco is also popular for the wide range of textures that can be created on its surface. You may find it in the texture of granite, brick, stone and traditional stucco.

Synthetic Stucco Defects

As mentioned above, this type of stucco is prone to develop certain problems. It has also been contented that most of the defects of this stucco arise from faulty installation procedures.

Moisture - The Major Synthetic Stucco Problem

As compared to traditional stucco that leaves some space between the substrate and the inner layer of the stucco, synthetic ones are directly attached to the substrate with adhesives. Besides that, synthetic stucco is non-porous in nature and does not allow any air circulation through its layers. So, if by any chance, moisture creeps in between the sheathing and the stucco, it is retained for long, thereby leading to rotting and damage to inner wall structures. Usually, moisture intrusion is not due to any problem with the stucco, but, it could be due to faulty installation of the stucco or leaks at the wall joints or in inner water structures. Even those window flashings that are improperly installed can cause this problem. Another reason is the moisture seepage from the ground. Even vents and other openings like, wiring, hose bibs and electrical boxes can cause this problem, if sealed improperly. Such trapped moisture may also lead to mold and mildew too.

Other Synthetic Stucco Defects

While moisture is found as the major problem with synthetic stucco, there are some other defects too.
  • This include the combustibility of the inner foam board used in this stucco. However, the possibilities of this foam board catching fire are very less, as it is covered with fiberglass mesh and top coatings.
  • This type of stucco may get slightly damaged if it gets subject to enough force. So, if something strikes on the wall with enough force, the surface may develop dents that may be an entry point for water or moisture.
  • In buildings, where the lower part of the stucco is below ground or is in touch with ground, moisture may easily seep in, causing problems. It may also happen that this makes an easy way for pests like ants and termites.
The above said is only a brief overview about EIFS stucco problems. Now, you must have understood that faulty installation is among the major causes for synthetic stucco defects. In short, you have to enough precautions to prevent such problems, if you intend to use this type of stucco. You must make sure that all the exterior joints and holes are caulked properly, so as to prevent water from entering stucco layers. Seal the edges of the stucco, especially those near the ground. Even the foundation has to be sealed. Watch out for those stucco cracks that have to be sealed at the earliest. So, install synthetic stucco in the proper manner and try to maintain it in good state.

Disclaimer: This article is for informational purposes only. You must gain a thorough understanding about synthetic stucco problems, from a person who is an expert in this field or from the manufacturer himself.