The Truth About Stucco
Introduction
Types of Stucco
EIFS Characteristics
Hardcoat Characteristics
Moisture: Stucco's Hidden Problem
The Hardcoat Myth
Stucco Bottom Cutting
The Stucco Solution
Stucco Inspection Protocols
Stucco Inspector Qualifications
The Pro-Spect Stucco Inspection Report
After Remediation: How to Maintain Stucco Exteriors
How to Sell a Stucco Home
Introduction
With the posible exception of composite siding and polybutylene pipe, perhaps no other building material has been maligned more than stucco (particularly synthetic stucco). Unlike composite siding and polybutylene pipe, however, the problems associated with stucco are almost exclusively related to installation and not in the design of the material itself. When improperly installed, stucco exteriors can become a moisture intrusion nightmare, often resulting is significant wood rot and even damage to load-bearing framing.
When properly installed or remediated, and if properly maintained, no other exterior cladding provides its homeowner with such an upscale appearance reminiscent of European and Mediterrean styling as does stucco.
Types of Stucco
In Georgia, there are essentially two types of stucco systems used in residential construction: Exterior Insulating Finish System (EIFS), or synthetic stucco, and hardcoat. Regrettably, these two systems are oftened compared to each other with hardcoat being touted as the superior system. This is particularly true in the real estate industry where many agents refuse to show EIFS homes to their clients for fear of being sued if problems arise after the sales transaction. "For Sale" signs abound with banners that proclaim "real" and "hardcoat' stucco. In reality, EIFS and hardcoat are two distinctly different types of exterior claddings both of which have individual pros and cons.
Hardcoat is believed by many to be exempt from the moisture problems that are typically associated with EIFS. This is an absolute myth (read our article titled "The Hardcoat Myth" by clicking here). In a recent study conducted by the Oak Ridge National Laboratory comparing EIFS, hardcoat, brick, and cementitious fiber board, EIFS was determined to be superior in terms of moisture resistance and insulating properties (see the highlighted portions of the study). The characteristics of both types of stucco systems are outlined below.
Hardcoat is believed by many to be exempt from the moisture problems that are typically associated with EIFS. This is an absolute myth (read our article titled "The Hardcoat Myth" by clicking here). In a recent study conducted by the Oak Ridge National Laboratory comparing EIFS, hardcoat, brick, and cementitious fiber board, EIFS was determined to be superior in terms of moisture resistance and insulating properties (see the highlighted portions of the study). The characteristics of both types of stucco systems are outlined below.
EIFS Characteristics
EIFS stands for Exterior Insulating Finishing System. It is also referred to as "artificial"" or "synthetic" stucco. Technically, EIFS is not stucco: it is an insulating exterior cladding with a stucco appearance. EIFS was designed as an energy efficient exterior covering and was heralded in the 70s and 80s as an innovative alternative to hardcoat, or "real" stucco that provided the upscale look of stucco while providing the homeowner with significant savings on heating and cooling costs.
Essentially, EIFS consists of polysterene panels covered with a fiberglass mesh and two thin layers of stucco installed over plywood, oriented strand board, or gysum substrates. Some versions of EIFS was installed as insulating foam panels covered with mesh and a finish coat of stucco directly attached to the exterior framing studs. Below is an example of an EIFS design and a photo of an actual EIFS wall:
Essentially, EIFS consists of polysterene panels covered with a fiberglass mesh and two thin layers of stucco installed over plywood, oriented strand board, or gysum substrates. Some versions of EIFS was installed as insulating foam panels covered with mesh and a finish coat of stucco directly attached to the exterior framing studs. Below is an example of an EIFS design and a photo of an actual EIFS wall:
- Upscale appearance.
- Less expensive than hardcoat.
- Saves 20 to 30 percent on home energy costs.
- Resists cracking.
- Easier than hardcoat to install.
- Susceptible to moisture intrusion if not properly installed.
- Vulnerable to impact damage and bird holes.
- May delaminate (separate from wall attachments) if moisture intrudes.
- Negative perception by general public and some Realtors.
Hardcoat Characteristics
Hardcoat, or "real" stucco, consists of a substrate (usually oriented strand board or plywood), a moisture wrap or weather resistive barrier, a wire lathe to hold the stucco in place, and several coats of stucco consicting or lime sand and portland cement. Below is an example of a hardcoat design and a photo of an actual hardcoat wall.
Hardcoat Advantages:
Moisture: Stucco's Hidden Problem
The Hardcoat Myth
- Upscale appearance.
- Resistant to impact damage.
- Perceived to be better than EIFS by the general public and some Realtors.
- Susceptible to moisture intrusion if not properly installed.
- Cracking is common.
- Moisture damage is often more widespread and expensive to repair when compared to EIFS.
- More expensive than EIFS.
- Low insulating properties when compared to EIFS.
Moisture: Stucco's Hidden Problem
EIFS and hardcoat share a common problem: moisture intrusion. Both systems are barrier type claddings. Barrier systems are not designed to drain should moisture intrude behind the stucco. Problems occur when poorly installed or missing caulking and flashing allow water to leak into the space behind the systems. Since both systems were designed to keep moisture out, moisture that does penetrate the system has no way to escape and remains trapped within the wall.
The vast majority of stucco homes in Georgia were not constructed to the stucco manufacturers' intended designs and most stucco installation instructions were never read or followed. Many stucco systems have never been properly caulked (or not caulked at all) and are missing critical flashings that can prevent the majority of moisture from penetrating the system. Windows have proven to be a major source of moisture penetration in stucco homes due to gaps or cracks in their construction. Double hung windows are particularly susceptible to moisture penetration that eventually makes it way to the wall cavity. It is important to note that even a small amount of moisture can create substantial damage to load-bearing framing components since it often takes many months for the moisture to dissipate or evaporate from behind the stucco.
While windows and flashings are the primary sources of moisture penetration behind the stucco cladding, any breach, gap, crack, or opening in the system is a potential avenue for moisture intrusion. Other examples of moisture penetration sites in stucco are:
While windows and flashings are the primary sources of moisture penetration behind the stucco cladding, any breach, gap, crack, or opening in the system is a potential avenue for moisture intrusion. Other examples of moisture penetration sites in stucco are:
- Deck attachments
- Hose bibbs
- Utility breaches (light fixtures, electrical outlets, gas pipe penetrations, etc.)
- Shutter attachments
- Porch and patio joints
- Downspout fasteners
- Chimney caps
-
Roof "dead" valleys
Below are some actual photos taken by
Pro-
Spect Stucco Inspectors during actual inspections depicting damage resulting from improperly sealed wall openings/breaches:
The photo at the top left depicts damage to the gypsum substrate in a crawl space directly an unsealed double hung window in an EIFS home. The photo at the top right is an example of the significant damage that can concealed behind a perfectly normal appearing stucco wall. Over $18,000 in repairs was required to replace the rotted load-bearing framing and oriented board substrate located below a missing kickout flashing. Cost to install a kickout: $225!
The Hardcoat Myth
Moisture problems directed attributable to installation errors began to surface in EIFS homes in the early 1990s. Class action lawsuits and major network news stories focused on the nightmares being shared among unhappy EIFS homeowners. As a result of the intense publicity surrounding this issue, and fearing legal libaility exposure, professional real estate agents began to avoid listing and showing EIFS homes. However. hardcoat stucco was continuing to be seen as a "problem free" exterior and for sale signs prominently displayed banners proclaimimg "real" stucco. Today, hardcoat is still generally considered superior to EIFS by many members of the real estate industry. This is what we refer to as "The hardcoat myth".
Hardcoat stucco does not seal the home as thoroughly as EIFS, and some of the moisture that penetrates the system is able to evaporate through the hardcoat stucco itself. However, hardcoat will tend to have almost identical problems to EIFS. Flashing locations and windows can allow moisture to enter the wall cavity thereby damaging structural wood. When moisture regularly penetrates hardcoat stucco, the wood structure behind the stucco often remains wet on a continuous basis. The constant presence of this moisture causes the wood framing to eventually rot.
Hardcoat stucco does not seal the home as thoroughly as EIFS, and some of the moisture that penetrates the system is able to evaporate through the hardcoat stucco itself. However, hardcoat will tend to have almost identical problems to EIFS. Flashing locations and windows can allow moisture to enter the wall cavity thereby damaging structural wood. When moisture regularly penetrates hardcoat stucco, the wood structure behind the stucco often remains wet on a continuous basis. The constant presence of this moisture causes the wood framing to eventually rot.
There are two more components to the hardcoat problem: the wire lathe and the actual stucco mixture itself. Because hardcoat stucco is held in place by a wire lathe, water can travel horizontally along the lathe resulting in moisture accumulation several feet away from the original water penetration point. This creates problems for the inspector attempting to determine areas of elevated moisture in hardcoat homes. Because hardcoat is a mixture of lime, sand, and portland cement, the exact proportions of each compound must be mixed or the hardcoat can become soft, brittle, crumble, of fall off the exterior wall in large sections.
The photos below were taken from a hardcoat home in Metro Atlanta by one of our stucco inspectors. Both photos were taken from the same location. The photo on the left shows a beautiful hardcoat surface with no visible defects or problems. The photo on the right was taken after our inspection revealed significantly elevated moisture and soft substrate and the stucco contractor opened the wall for a visual evaluation.
Damage to load-bearing framing was extensive and widespread. Water had move along the lathe system for approximately 10 feet damaging both framing and door and window components. Ironically, the homeowner had initially refused to allo our inspector to conduct moisture probing stating "there is obviously nothing wrong with the stucco". This is one of many examples of concealed damage that goes undetected every day because of the mistaken belief that hardcoat is not subject to the same moisture problems as EIFS. Some buyers, adopting this belief, would have purchased this home without obtaining a professional stucco inspection.
The next set of photos were taken in September of 2007 during an inspection of another hardcoat stucco home in Metro Atlanta. In this case, the original stucco contractor failed to mix the correct proportions of lime, sand, and portland cement during the home's construction. The results were disasterous: the stucco had completely deteriorated into a crumbling, sandy mess. Large sections had already fallen off of the exterior and the stucco was so soft that it could be penetrated by pushing against it with your finger. Damage was so pevasive that complete tear off and replacement was required. The cost: $98,000.
While hardcoat has some advantages over EIFS, resistance to moisture intrusion and damage to wood components behind the stucco is not one of them. A properly-conducted stucco inspection, to include moisture probing, is the only means to determine the true condition of the system.
Stucco Bottom Cutting
There is one particular stucco area that merits separate discussion: the bottom of the system. When the bottom of an EIFS wall contacts or extends below the ground surrounding the building (grade), water can "wick" up the foam EPS insulation, resulting in moisture damage to the bottom of the framing and attracting termites and other insects. To solve this problem, a professional stucco contractor will make a 45 degree cut into the bottom of the system, remove 6 or more inches of the foam insulation, replace the foam with concrete backer board, and backwrap and seal the entire area with fiberglass mesh and finish coats of stucco. When properly done, a pleasing appearance is obtained. Improperly cut stucco bottoms can destroy the home's appearance.
Although hardcoat does not contain foam insulation, the plywood or oriented strand board (OSB) to which the stucco is applied can rot and provide a path for termites if it contacts the ground. Therefore, hardcoat is often cut and sealed to satisfy local code and pest control company requirements. Check with your pest control company to determine if they require cutting hardcoat to maintain your termite bond.
One final thought on bottom cutting: some stucco and pest control contractors dig a trench around the perimeter of stucco homes to establish the required ground clearance. Not only is this an improper remediation method, leaving a trench around any home creates a far greater problem that possible insect infestation: water will pond in the trench after heavy rains which can result in significant foundation settlement or damage and flooding of basement and crawlspaces. The 6 inches of clearance between the bottom of the stucco and the ground must be established while maintaining a positive grade (slope) away from the foundation wall to promote proper surface drainage.
Below are photos of bottom cuts. The photo on the left depicts a poorly conducted cut with the mesh and bottom of the foam board exposed. Water can travel along the mesh and be wicked up into the exposed foam. The photo on the right shows a professionally cut and sealed stucco bottom.
Below are photos of bottom cuts. The photo on the left depicts a poorly conducted cut with the mesh and bottom of the foam board exposed. Water can travel along the mesh and be wicked up into the exposed foam. The photo on the right shows a professionally cut and sealed stucco bottom.
The Stucco Solution
By now you are probably getting the idea that a stucco home can be a real nightmare. And, as we have stated, almost none of the EIFS and hardcoat stucco homes constructed in Georgia were done so properly. However, there is a three-step solution that can transform improperly-constructed stucco homes into buildings requiring average maintenance and that are no longer susceptible to moisture intrusion problems:
- Stucco Inspection
- Stucco Remediation
- Stucco Reinspection
The path to worry-free stucco home ownership starts with a thorough inspection conducted by a
Pro-
Spect
stucco inspection professional. In a few short hours (usually less than 3), we will develop a precise assessment of the condition of your stucco system, identifying the defects that, when corrected, will insure you a home free from stucco moisture problems. This information is provided, at your request, to up to three Certified Stucco Remediation Contractors who will develop a scope of work and cost estimate for correcting the conditions discovered during the stucco inspection. After the stucco contractor completes the remediation process, we conduct a reinspection to confirm that all work has been properly conducted to current industry standards. You now have a home that is both beautiful and protected against moisture intrusion.
Stucco Inspection Protocols
Unfortunately, there is no single reference that encompasses every requirement for conducting stucco inspections. Therefore, the Pro- Spect inspection protocol was developed using a variety of industry requirements including:
Over the years, some of our clients have told us that other inspectors with whom they communicated have stated that they use moisture scanners to detect moisture and that it is not possible to conduct moisture probing on hardcoat stucco homes. Scanners, such as the Tramex Wet Wall Detector, should not be used as primary moisture detection devices because they give false positive indications when passed over metal such as nails, foil-backed insulation, and some wiring. The only acceptable method for determining if moisture exists behind a wall is to probe the wall with a primary moisture detector such as the delmhorst BD2100. Scanners are useful in "mapping" the elevated moisture area but should only be used after elevated moisture is detected using a primary probing meter.
With regard to hardcoat, moisture probing is not only possible, it is essential in determining if moisture is present . It is true that contacting the metal lathe behind the hardcoat with bare probes will give a false positive reading. However, this possibility is eliminated by insulating the metal probes with rubber shrink wrap or electrical tape. The damage that appears in the photos shown above (under "the Hardcoat Myth" section) was detected using a moisture meter with insulated probes.
Stucco Inspector Qualifications
Inspecting stucco systems requires unique training and experience and should only be attempted by a certified stucco inspector. Home inspectors, unless separately trained and certified to inspect stucco, should disclaim stucco exteriors as "beyond the scope of a general home inspection" and recommend that the stucco system be evaluated by a properly certificated stucco inspector. At minimum, individuals conducting stucco inspections should be either EDI or MWC certified ( Pro- Spect Stucco Inspectors are certified by both). AWCI Certification is also acceptable providing the inspector is current with the changes in existing home inspection protocols. Knowledge of MWC inspection protocols is critical if the client is seeking a MoistureFree Warranty or if the home may be sold to someone requesting a warranty.
In addition to holding the proper certifications, a professional stucco inspector should not have any financial or employment interest in any company or organization that conducts stucco repairs or remediation. Stucco remediation companies that also conduct inspections have a built-in conflict of interest. Having a stucco contractor inspect his or her own work is comparable to allowing a homebuilder to conduct his or her own home inspection. Hiring a Pro- Spect independent stucco inspector can save you thousands os dollars in unecessary repairs and is your insurance that the remediation will be completed to industry standards.
The Pro- Spect Stucco Inspection Report
All Pro- Spect Stucco Inspection Reports are written to MWC and other industry standards, are easy to follow, and contain dozens of detail photographs and moisture readings. To view an actual stucco inspection report, click here (please allow several seconds for the report to fully open).
After Remediation: How to Maintain Stucco Exteriors
After all installation defects have been remediated, stucco homes do not require any more maintenance than homes with other types of exterior claddings. We recommend having a visual inspection conducted 18 months after the initial inspection and every two years thereafter. Minor wood rot, often undetectable during the initial inspection, can worsen over time. Also, some sealant joints may fail during the first 18 month period after remediation due to caulk being applied over uncleaned surfaces.
In addition to periodic inspections, normal maintenance and cleaning is required. Use a garden hose with a small orifice nozzle to remove any dirt and minor mildew from the stucco surfaces. For heavier buildups, use a solution of 1 gallon of warm water and 1 cup of trisodium phosphate (TSP) or dish washing liquid applied with a soft bristle brush. Do NOT use a high pressure washer to clean stucco surfaces! Pressure in excess of 600 psi can damage stucco finish coats (as can hard bristle or wire brushes).
Rust or copper stains can be removed using Sure Klean Ferrous Stain Remover (available at most hardware and home improvement stores). Painting should be accomplished by a professional contractor. However, do NOT allow a painting contractor to apply caulk to any joint on a stuco exterior! Caulk joints require special materials, skills, and techniques that only a professional stucco contractor will possess. Paint should be approved for stucco surfaces. Most stucco homes do not require painting. However, if painting is desired or needed, do NOT use an elastomeric type paint on EIFS. Elastomomeric paints seal the exterior surfaces and do not allow EIFS systems to "breathe".
How to Sell a Stucco Home
Selling an EIFS or hardcoat stucco home can be challenging. Unfortunately, many uninformed real estate progessionals refuse to even show an EIFS home to their clients and others insist that a stucco inspection and warranty be provided by the seller. If you are confronted with these problems, we can help! The following simple steps will provide your prospective buyers with the assurance that they are purchasing a home free of moisture problems and not a "money pit":
Stucco Inspection Protocols
Unfortunately, there is no single reference that encompasses every requirement for conducting stucco inspections. Therefore, the Pro- Spect inspection protocol was developed using a variety of industry requirements including:
-
Stucco System Manufacturer's Installation Instructions. Every manufacturer of EIFS and hardcoat stucco materials, components, and systems publishes specific installation instructions to include detailed diagrams, photographs, and drawings. These instructions are used as the primary inspection criteria for newly-constructed stucco homes. Because existing stucco buildings are inspected and remediated differently than those currently being constructed, manufacturer installation instructions cannot be used to evaluate these homes.
-
Building Codes . Unfortunately, there are few building codes that address stucco construction (Georgia Code defers to manufacturer's installation instructions). The most prominent remaining building code that applies to stucco is the requirement that all stucco exteriors terminate a minimum of 6 inches above the surrounding grade (to prevent termite and other pest infestation).
-
Exterior Design Institute (EDI). EDI is the largest third-party stucco inspector certification and membership organization in the
- Moisture Warranty Corporation (MWC). MWC is the largest and most prominent moisture warranty provider in the nation, specializing in providing protection to stucco buildings. During the Dryvit Class Action Lawsuit, MWC was selected by the U.S. Federal Court to develop inspection and remediation protocols applicable to existing stucco homes. During this process, MWC conducted exhaustive research on how moisture enters stucco-cladded buildings, using the information obtained during these tests to develop protocols for identifying and correcting stucco moisture problems. The MWC protocol was accepted by all parties involved in this lawsuit to include stucco contractors, applicators, and the Dryvit Corporation and have subsequently become the de facto industry standard for inspecting all existing stucco homes.
Over the years, some of our clients have told us that other inspectors with whom they communicated have stated that they use moisture scanners to detect moisture and that it is not possible to conduct moisture probing on hardcoat stucco homes. Scanners, such as the Tramex Wet Wall Detector, should not be used as primary moisture detection devices because they give false positive indications when passed over metal such as nails, foil-backed insulation, and some wiring. The only acceptable method for determining if moisture exists behind a wall is to probe the wall with a primary moisture detector such as the delmhorst BD2100. Scanners are useful in "mapping" the elevated moisture area but should only be used after elevated moisture is detected using a primary probing meter.
With regard to hardcoat, moisture probing is not only possible, it is essential in determining if moisture is present . It is true that contacting the metal lathe behind the hardcoat with bare probes will give a false positive reading. However, this possibility is eliminated by insulating the metal probes with rubber shrink wrap or electrical tape. The damage that appears in the photos shown above (under "the Hardcoat Myth" section) was detected using a moisture meter with insulated probes.
Proper Use of Moisture Probing and Scanning
Stucco Inspector Qualifications
Inspecting stucco systems requires unique training and experience and should only be attempted by a certified stucco inspector. Home inspectors, unless separately trained and certified to inspect stucco, should disclaim stucco exteriors as "beyond the scope of a general home inspection" and recommend that the stucco system be evaluated by a properly certificated stucco inspector. At minimum, individuals conducting stucco inspections should be either EDI or MWC certified ( Pro- Spect Stucco Inspectors are certified by both). AWCI Certification is also acceptable providing the inspector is current with the changes in existing home inspection protocols. Knowledge of MWC inspection protocols is critical if the client is seeking a MoistureFree Warranty or if the home may be sold to someone requesting a warranty.
In addition to holding the proper certifications, a professional stucco inspector should not have any financial or employment interest in any company or organization that conducts stucco repairs or remediation. Stucco remediation companies that also conduct inspections have a built-in conflict of interest. Having a stucco contractor inspect his or her own work is comparable to allowing a homebuilder to conduct his or her own home inspection. Hiring a Pro- Spect independent stucco inspector can save you thousands os dollars in unecessary repairs and is your insurance that the remediation will be completed to industry standards.
The Pro- Spect Stucco Inspection Report
All Pro- Spect Stucco Inspection Reports are written to MWC and other industry standards, are easy to follow, and contain dozens of detail photographs and moisture readings. To view an actual stucco inspection report, click here (please allow several seconds for the report to fully open).
After Remediation: How to Maintain Stucco Exteriors
After all installation defects have been remediated, stucco homes do not require any more maintenance than homes with other types of exterior claddings. We recommend having a visual inspection conducted 18 months after the initial inspection and every two years thereafter. Minor wood rot, often undetectable during the initial inspection, can worsen over time. Also, some sealant joints may fail during the first 18 month period after remediation due to caulk being applied over uncleaned surfaces.
In addition to periodic inspections, normal maintenance and cleaning is required. Use a garden hose with a small orifice nozzle to remove any dirt and minor mildew from the stucco surfaces. For heavier buildups, use a solution of 1 gallon of warm water and 1 cup of trisodium phosphate (TSP) or dish washing liquid applied with a soft bristle brush. Do NOT use a high pressure washer to clean stucco surfaces! Pressure in excess of 600 psi can damage stucco finish coats (as can hard bristle or wire brushes).
Rust or copper stains can be removed using Sure Klean Ferrous Stain Remover (available at most hardware and home improvement stores). Painting should be accomplished by a professional contractor. However, do NOT allow a painting contractor to apply caulk to any joint on a stuco exterior! Caulk joints require special materials, skills, and techniques that only a professional stucco contractor will possess. Paint should be approved for stucco surfaces. Most stucco homes do not require painting. However, if painting is desired or needed, do NOT use an elastomeric type paint on EIFS. Elastomomeric paints seal the exterior surfaces and do not allow EIFS systems to "breathe".
How to Sell a Stucco Home
Selling an EIFS or hardcoat stucco home can be challenging. Unfortunately, many uninformed real estate progessionals refuse to even show an EIFS home to their clients and others insist that a stucco inspection and warranty be provided by the seller. If you are confronted with these problems, we can help! The following simple steps will provide your prospective buyers with the assurance that they are purchasing a home free of moisture problems and not a "money pit":
- Receive a thorough inspection, to include moisture probing, from one of Pro-Spect's EDI and MWC Certified Stucco Inspectors.
- Have all stucco deficiencies and moisture damage repaired by a MWC Certified Stucco Contractor.
- Obtain a post-remediation inspection to confirm that the stucco repairs have been properly conducted and that the remediation was successful.
- Pro- Spect will provide you with stucco Certificate of Condition stating that the stucco cladding on your home meets, or exceeds, all current industry standards.
- Place a Pro- Spect yard sign, provided to you at no additional cost, in your front yard to let all Realtors and prospective buyers know that your home's stucco has been professionally inspected and remediated.
Click on certificate for full size view