Q: What is EIFS?

A: EIFS stands for Exterior Insulated Finish System. EIFS is a relatively new product which uses plasticizers to modify traditional cement stucco and make it more flexible. This allows application in a thinner coating which saves time and material. The entire modern EIFS system consists of a moisture barrier (usually), the foam insulation, the plastic-cement basecoat, fiberglass reinforcing mesh, and finishes. 


Q: What is the issue with older EIFS?

A: Prior to the late 1990's, most residential EIFS did not incorporate a moisture barrier behind the system.  The older system is now referred to as "Barrier EIFS."  In order to protect the building from moisture intrusion, barrier EIFS must be perfectly sealed at the outside surface. Any moisture that penetrates the outer coating can easily migrate into the walls and cause substantial damage. Unfortunately, nothing is perfect, and the material tends to leak. Sometimes it leaks quite a bit. The weak point of most applications is the penetrations like windows, doors, electric and other utilities, etc. Each of these is a potential leak.  Even though most manufacturers withdrew their barrier EIFS from the residential market in the late 1990's, we still occasionally see these systems being installed today.


Q: What is the issue with newer EIFS?

A: Since the late 1990's the major manufacturer's of EIFS system have come out with the newer water management EIFS systems. They incorporate a secondary drainage plane that provides and escape route for any water that makes it through the outer skin of the system. These systems are well designed, but unfortunately they rely upon installation details that are completely concealed after the system is completed. We are finding many homes built in this millennium that have severe water damage due to poor detailing by the installers. The other key issue with the newer system is that, just like with the older barrier systems, that can look perfect on the outside, yet be totally rotten on the inside.


Q: How do I know if my EIFS is leaking?

A: First, it is important to understand that ALL EIFS is leaking. The important question is: How Much? As long as a wall is built to dry faster than any leaks can wet it, there can be few problems. Issues occur when the water comes in faster than it goes out. Materials that stay wet for long periods tend to rot, grow mold, and then eventually fall apart. Here in Utah, we find that many walls show signs of leakage and elevated moisture, but that the damage caused by these leaks is less severe than in other parts of the country. Still, over 80% of the houses we have inspected have at least some structural damage caused by water leakage and entrapment within the walls.


Q: So how can I tell if water is building up in my walls?

A: It is only with a comprehensive moisture intrusion inspection can we identify the issues behind the stucco. There are many different methods and tools that can be used to identify potential trouble spots. Regardless of how suspect areas are identified, you cannot know exactly how much moisture is trapped without penetrating the EIFS and directly measuring the moisture content of the building materials inside. There is just no other way. This has been established by a number of nationally accepted test protocols, including the one we follow. You can see our test protocol by visiting the GAHI website. The GAHI protocol states in part, "The advent of the Tramex Wet Wall Detector has eased the process of inspection. This tester will indicate areas with high or elevated moisture content. This tester will not provide specific moisture content information. An intrusive probe is required for the determination of specific moisture content."


Q: Is a non-invasive inspection adequate?

A: In most cases the answer is "No." Some other inspectors are touting their "non-invasive" inspections. Be very careful before deciding on this type of inspection. We, Michael Leavitt & Co Inspections, Inc., also use the non-invasive scanner (Tramex Wet Wall Detector, or WWD) to identify wet areas within the walls, but only as a part of the complete moisture evaluation service. The manufacturer of the most popular scanner (Tramex) indicates in their user's manual that, "When the WWD has been zeroed correctly on a dry area and set on the correct range for the EIFS thickness, a higher than zero reading normally indicates higher moisture content." Read this statement very carefully.

In order for the meter to behave "normally", the test technician must know the thickness of the EIFS and the moisture content of the wall behind it. There is no way to know these critical pieces of information without penetrating the EIFS for the calibration step. If the meter was accidentally zeroed over a wet area, then the technician would miss ALL other wet areas on the house. In addition, the manufacturer says that higher readings "normally" indicate higher moisture levels.


What about false positive readings? - It is common for metal inside the walls to provide a false positive reading, indicating that moisture is present when in fact, there is none. We often encounter high readings with the WWD and find satisfactory moisture levels inside the wall with an invasive probe. The manufacturer also recommends in several places in their user's manual that the WWD results be checked using a penetrating probe.


Q: Will infrared thermal imaging cameras work?

FlirA: There are also EIFS inspectors who rely on infrared thermal imaging cameras to determine wet areas behind EIFS.  Just like with the Tramex WWD, the camera is easily fooled.  They can tell when water is just below the skin of the EIFS, but the thick foam disguises the conditions of the wood from the infrared camera. I have tried using them on dozens of EIFS clad homes without any real success.

Infrared cameras are also very sensitive to weather conditions (the best images can often be taken only for an hour or so after sundown), and to normal wide variations in field conditions.  They are prone to both false positives and false negatives.  IR cameras can be a very useful scanning tool, but again, you only know for sure how much water and damage may be behind the system by inserting probes and measuring it.

LET ME RESTATE... Infrared Thermography is NOT the best solution for determining the extent of water damage behind the stucco. The foam in EIFS and/or hardcoat stucco thickness conceal what is really going on with the wood framing. Don’t be fooled by those touting the infrared camera as quick, easy, cheap, and surefire non-invasive test for water entry behind stucco. This myth is perpetuated by those without the needed experience to accurately test for water damage behind stucco, and one that real estate agents love to disseminate without knowing any better as the myth seems like the easiest way to pacify a worried buyer.

WARNING: Beware, there are many home inspectors out there with their new infrared toy willing to take your money for the severely inadequate non-invasive test.

See the fuller response... THERMAL IMAGING MYTH


Q: Is probing the most reliable method of testing?

A: Short of removing the entire system, probing is the best method of testing EIFS stucco systems. As for other testing equipment, even the very smartest Engineers at Tramex and the infrared camera companies have not yet been able to find a way that their equipment can accurately measure the moisture content of the walls independent of invasive probing. What do the other inspectors know that the manufacturer's own Engineers do not? Use of these tools is an important part of a comprehensive moisture intrusion inspection, but it cannot alone give the complete and necessary information you need to properly understand the scope of any moisture problems the house may have. A house is a big investment, and EIFS issues can be expensive to repair. Do yourself a favor and hire someone who performs a complete and proper inspection.


Q: When you talk about "penetrating the EIFS", just how big of holes do you make?

A: The moisture meter uses two narrow probes that require holes the size of an ice pick. Many people in the industry refer to this as a "snakebite." After testing, the holes are sealed with an appropriate caulk that is compatible with the color of the EIFS. Because of the texture of the material, the patches are generally invisible.


Q: Are there other EIFS issues beyond structural decay?

A: Yes. Some molds can cause injury or ill health to people sensitive to them.  There is a surprising amount of air exchange between wall cavities and the indoor rooms in a house. The air currents can carry mold into the living spaces of a house.  There are currently no public health standards concerning unsafe mold levels or unsafe types of mold, but a prudent homeowner will clean up any known mold sites and eliminate the moisture problems that allowed the mold growth. An industrial hygienist familiar with mold exposure and cleanup can provide further information.


Q: If my walls are wet, do I have to remove all of the EIFS?

A: Not necessarily. It depends very much on how wet they are, how long they have been wet, and how much area is affected. Corrections can range from:

  • simple caulking and sealing,
  • to partial removal and repairs,
  • to complete removal of the system and structural repair to the walls behind.

The EIFS test probe moisture measurements will help you to make the final decision as to the needed full scope of repairs.


Q: Is there a solution for the EIFS water entry issues?

A: Yes. All of the major manufacturers are now selling products that drain. They use different approaches to provide a drainage plane behind the EIFS so that any moisture that leaks through the outer barrier can drain away to the base of the wall, and seep to the outside. When properly installed, they dramatically improve the performance over the older barrier EIFS. Of course, they will still be sensitive to proper installation, like any exterior siding system.


Q: If I have drainable EIFS, can I still have a issues?

A: Yes. Now that drainable systems have been on the market for 10 years or so, we have had time to see them in action.  When correctly applied, they work well.  Unfortunately, many builders do not follow the manufacturer's instructions, and if the backup water barrier is not done well, these systems exhibit the same failure modes as the older barrier EIFS.  We generally see less leakage and damage with drainable systems than with barrier systems, but we have now seen dramatic failures with both types.  Again, a comprehensive moisture evaluation is the best way to know how well your system is performing.


Q: Where can I go for more information?

A: You are welcome to contact us directly. We do our best to provide fast responses. If you want to hear the party line directly from the manufacturers, go to the EIFS Industry Member's Association, EIMA. If you want a homeowner's perspective, simply do a web search on EIFS - there are many thousands of sites discussing the issues. Please remember to think critically when visiting any website. Do your best to ascertain the bias of the site so that you can effectively weigh the information presented.

Please keep researching the information that we are sharing on our site and we encourage you to use us for your stucco inspection needs.


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