What exactly is EIFS (pronounced E-E-F-S)?
EIFS is an exterior wall finishing system that has the appearance of stucco. It was developed in Europe over 40 years ago as an efficient way to insulate buildings from the exterior rather than from the interior. In Europe most exterior walls are solid masonry with no cavities for insulation.
It was introduced to the United States in 1969 under the brand name, DRYVIT. Since its arrival, it has been used for both commercial and residential installations.
Currently, it is being used in over 30 states, and that number continues to grow.
While having the appearance of stucco, EIFS is actually a multi-layered system that acts like several layers of clothing keeping the elements out on a cold day. The outer layer is an acrylic finish coat that acts as a water barrier, shedding moisture and protecting the inner layers. Behind this layer is a base coat with an embedded fiberglass mesh. This layer adds impact strength to the finish (keep in mind that EIFS is a non-structural component of the wall).
The innermost layer is a 5/8 to 4" thick layer of insulation, usually expanded polystyrene or polyiocyanurate. This layer provides the insulating factor and allows aesthetic joints and features to be added which contributes to the depth to the siding. Properly installed and maintained EIFS will provide years of service.
So what’s the problem?
By the mid-70's there were several other manufacturers of EIFS components, and its use in residential construction grew rapidly. The problems that occurred resulted mostly from installing the materials over wood framing instead of over masonry as in Europe. This, coupled with a lack of experienced installers, resulted in major problems by the late 80's.
The resulting damage in most cases was from moisture getting behind the siding and rotting the substrate and wall framing materials. Due to the growth of the industry, there were not enough experienced installers and drywall plasterers and painters became installers. Being totally unfamiliar with exterior flashing and terminations, they installed it the way they would plaster interior walls. Failures developed at roof rakes, chimneys, floor lines, and around windows, doors and protrusions. Installation "Details" were developed as a result of the lessons learned during those first few years in the United States. "Details" have become the industry installation standards. Each manufacturer has its own version, but they are basically similar. Failure to follow the manufacturer's installation instructions and "Details" allows moisture to get into the wall system, and it can't get out. The cladding material is a water barrier - once water gets in, it cannot flow out. It has to evaporate and get out as a water vapor. During this extended time the wood absorbs the moisture, which can allow wood rot when the moisture concentration is in excess of 30%.
A National Relocation Inspection Service Company said that over a 10-month period they had completed over 400 Synthetic Stucco Inspections. The results showed that in all but one home there was some level of problem, ranging from as slight as caulk in some seams to a total replacement with an estimated cost of $100,000 on a $450,000 home. Of the last 100 homes I inspected in the Kansas City Metro Area, though most were close, none of the 100 had EIFS installed to manufacturer's specifications. None were over twelve (12) years old. All needed some repairs, most under $2,000. In all cases, it was a result of improper installation. Please be aware that all siding materials need to be installed correctly to manufacturer's specifications.
There is no such thing as a maintenance-free siding material. Plywood, Fiberboard, Brick, EIFS - all these materials need periodic repairs and maintenance. For example, fiberboard siding if not flashed, caulked, and painted properly can show similar problems as those of EIFS. Water gets behind the siding and causes deterioration of the framing members, and the depth of the problem is hidden behind the siding.
When contractors install EIFS, many times they install it incorrectly, and rainwater enters via cracks around doors and windows, and also where gaps exist like the one in the picture above at the meter pan conduit. This picture was taken in Mineola, N.Y. and the seller stated that "the BEST stucco company on Long Island" performed his siding installation. When the inspector arrived and showed the seller some of the problems, he was quite surprised. He spent over $35,000 on the siding installation!
The first problem for the home inspector is how to identify EIFS. Understanding the differences between hardcoat stucco, polymerbased EIFS, and Polymer Modified EIFS is important, as well as understanding the potential for moisture damage related to the various types. Recently, the industry released a drainable system to prevent water from becoming trapped in the wall cavity. It appears to be functional and the future of EIFS installations. What we have to do as inspectors is to be able to identify, analyze the potential problem areas, and report on our findings.
The NAHI Standards of Practice require member home inspectors to:
Inspect exterior wall covering, trim and protective coating.
Describe the type and material comprising the exterior components inspected.
- Observe the condition of the components from the ground level.
From the point of view of the homeowner, you may hear these questions:
Can I sell my home?
Yes, have it inspected and disclose the condition.
Will my homeowners insurance cover repairs due to moisture entry?
No, homeowner's insurance is for sudden and accidental damages and not for damage that occurs slowly over time, but check with your agent.
Is it repairable?
Yes, the vast majority of homes require only minimal repairs and ongoing maintenance.
What do I do to protect my investment?
Hire a trained professional to inspect the siding in its current condition, make the necessary repairs, and follow a preservative maintenance program.
Don't be afraid of EIFS. Things to be aware of include voids, openings, lack of flashing or any penetration. All these situations can allow moisture to enter the wall system. Once these voids are sealed, evaporation can start; and if it is caught soon enough, it can end the problem.
Is there a problem?
EIFS gives the appearance of stucco, at a much lower installed cost. The beauty of EIFS is that you have great flexibility in design and detail without greatly increasing the labor or cost. There are other advantages as well. Among these are increased insulation, lightweight construction, and a very forgiving material. EIFS materials, when installed correctly, consist of a foam board made of either polystyrene (white) or polyiocyanurate (beige). It is glued or mechanically fastened to the substrate. A polymer-based base coat, with a fiberglass mesh embedded in it, is installed over the entire surface and backwrapped around all edges. An acrylic polymer finish coat is then troweled over the entire surface. This finish coat is called the laminate. It presents a solid but flexible surface that is a vapor permeable water barrier.
The most notable concern with this type of siding material is that if not installed correctly, it will allow water to become trapped behind the siding. Water collects behind the siding material; and if not evaporated, will be absorbed by substrate materials and/or rots the interior finish surface. Moisture that gets trapped behind the siding is not visible to the eye until it has done damage. Consequently, the only means to determine if elevated moisture content is present is to do a moisture analysis. The procedure to follow is relatively simple, but it does take time.
How serious a problem is it?
A National Residential Relocation and Environmental Inspection Company stated, "Over a span of 10 months, we have conducted over 400 Synthetic Stucco inspections and have found varying degrees of damage on all but one home. The moisture penetration we have uncovered and the resulting damage has been as high as $100,000 on a home with a market value of $450,000."
How extensive is the use of EIFS?
According to a study commissioned by the National Association of Home Builders (NAHB), homes surveyed "ages two to six are experiencing structural damage due to excessive moisture buildup within walls. The cause of moisture accumulation is rainwater intrusion from a combination of factors including: improper sealing at joints and around windows, doors and other penetrations; improperly sloped horizontal EIFS surfaces; inadequate flashing at roof lines, dormers, decks, fireplace chases, etc., and window frames that leak into wall cavities." Moisture build-up and rotting was found to be insidious, as it could not be determined from a visual inspection.
EIFS is designed to be a face sealed barrier providing a weatherproof membrane. All water must be shed at the outermost surface of the EIFS lamina since water entering behind the base coat can enter the wall cavity. Therefore, watertight sealing around penetrations such as windows, doors, electrical outlets, vents, roofing, etc., is essential to maintaining the integrity of the EIFS. Moisture readings ranged from 18% to greater than 50% in sheathing near band joists below window and door openings."
NAHB RESEARCH CENTER FINDINGS, MARCH 1999:
In March of 1999, the NAHB Research Center found the following:
- When moisture has entered the wall cavity due to a leak, if the leak is sealed and no further water enters the system at the location during a period of 24 weeks, the moisture content will drop from 20% - 25% to an acceptable 10% - 12%.
If the wall cavity is made accessible, the interior vapor (poly) retarder should be removed.
With moisture content of 20% decay will start if left for extended periods.
Short repeated intervals of wet then dry are okay.
Fungus spores will germinate if moisture content is at least 25%.
Moisture content of 30% will hasten decay in most species of wood.
Mildew is a fungus that grows only on the surface and will not damage wood.
A humid climate alone will not cause mildew, but can lead to mold growth.
Both mold and mildew can be eliminated by drying out the area and wiping with a 10:1 water:bleach solution.
The NAHB undertook the task of determining what was happening for the industry. In March of 1999 they performed field research and evaluated 1200 homes in Wilmington, North Carolina, where they found the following:
350 had EIFS completely removed.
100 of the 350 were analyzed in detail before and after tear off moisture testing. Damage assessment completed.
Analysis of contributing conditions: That the water intrusion problems are most associated with:
Below grade installations.
Articulations and projections (minimal).
Problems in the field are minute.
The NAHB Research Center has a report, which was released in 1999, showing statistical analysis of the damage to homes. For information on this report, please contact the NAHB Home base hotline, technical service line, at 800-898-2842.
While much research appears to make the EIFS material at fault for damages to homes, in reality the EIFS materials may be performing quite well. However, the installation of the EIFS material appears to be one of the main problems. If the penetrations are correctly back wrapped with backer rods installed and sealed properly, the likelihood of moisture getting in would be reduced to the failure of sealants or a penetrating component.
The NAHB Research center has determined that of the needed repairs to homes with EIFS, the most serious water entry points are around windows and at kick-outs. The question now appears to be, does the EIFS fail at the areas adjoining these entry points, or is the damage possibly due to defective windows? There was a case involving a lawsuit against an EIFS installer in Colorado, and to everyone's surprise after reviewing all of the evidence, it was discovered that in spite of a less than quality installation, the bulk of the moisture damage noted came from the window design and their installation. Lack of correctly installed kick-outs at intersecting walls with rooflines is the second most likely leak location. It would be difficult to blame the EIFS when the lack of a flashing allows water to enter behind it.
Do other wall cladding materials have the same problems?
As noted previously, most wall siding materials used in the business today have similar problems. These problems are more common and significant on newer construction than on older homes. This is, in part, due to the tightness of the construction. Newer homes do not breathe the way older construction does. If a home cannot breathe, it cannot eliminate moisture. When you look at older homes, you see that they used bricks, boards, and shakes. All of these materials had voids that allowed not only water vapors to pass through, but they also allowed water to pass through in a liquid state.
New construction uses sheetrock with plastic sheeting vapor barriers behind it. Some homes also have polystyrene boards under the siding. Both of these materials retard the flow of moisture in either direction.
The next problem encountered with newer construction is the workmanship of the installation on the exterior. The biggest potential problem is that of an installer who did not follow the manufacturer's installation instructions. If the siding installation does not start out correctly, it is never going to get better.
Barrier versus drainage systems:
The original EIFS installation was designed as a barrier system back in the 1940's in Europe. It was used over masonry construction. If water were to penetrate the system, the water came in contact with masonry substrate and it was not a big deal as the small amounts of water would not damage the masonry wall structure. With the introduction of EIFS here in the United States, the system was used over masonry, mostly for commercial purposes. Now, in residential construction the framing is wood with wood and sheetrock substrate. The residential segment of the market is where moisture problems really showed up. There have been Class Action Lawsuits in North Carolina resulting from the moisture penetration. The manufacturers were hit hard before they were really able to show that the problems, in large portion, are due to the installation and not necessarily to the product itself.
Since all the problems and litigation have occurred, the industry manufacturers have developed a drainable system. The drainable systems all have several things in common - the one purpose is to allow water that does get behind the EIFS to drain out.
The drainable system has a vapor barrier installed against the substrate to prevent it from getting wet. This barrier extends down into an installed track that water can run into and then drip out at the front lower edge, away from the structure. This system will be more forgiving of an improper installation. The felt paper or barrier is fastened to the substrate so there will be screw and/or staple holes in the barrier for the foam, but in reality this will still be an improvement for a less than adequate installation.
Some limited areas of the country will now only allow the drainable system. You will be able to tell the correctly installed drainable system - the plastic bottom track has relief holes drilled into it. The base coat and mesh and lamina extend to the bottom edge of the track. If you see a crack along the top edge of the track, it tells you that the mesh was not extended to the bottom edge of the track and a repair is needed.
Completing a moisture analysis is well beyond the responsibility of a normal home inspection. In a home inspection you are responsible for component identification and a visual inspection of the structure and its components.
It is always recommended that when EIFS in present on a house, that a separate, detailed inspection by a licensed EIFS inspector be performed.