We begin with Phase 1, which is a preliminary visual evaluation of the home’s exterior. We encourage this to be done with the client present. At this time we are looking for visual cues about how the system is performing and how it was installed. We’ll walk the property and take note of visual evidence of cracking, staining, and key installation details, and also look for the absence or inclusion of certain elements – head flashing above windows and kickout flashing at roof-wall intersections, for example. When these (and other) elements are not present, it’s an indication that these areas may be vulnerable so we know we need to pay close attention as we move forward through the inspection. At this time the client is encouraged to discuss areas of concern or areas where moisture intrusion has already occurred (e.g. water staining around interior windows or doors) or where there has already been remediation work, caulking, etc. as the result of moisture intrusion issues or general maintenance.

Because it is impossible to see through walls in order to obtain facts about how the home is performing it is necessary to move into Phase 2 testing.  Phase 2 testing is an invasive testing procedure known as moisture probe testing. This requires us to drill 2 small holes, about an inch apart, and roughly the diameter of a pencil. Through these holes we insert a moisture meter to test the moisture content of the substrate behind the stucco, or the wooden part of the home. We're most concerned with testing portions of the home that are above the foundation and/or on a wooden substrate. We typically need to test and map out the most exposed areas on each wall section, such as the lower penetrations/first floor windows, as well as the roof-wall intersections and any other areas of the construction that are vulnerable based on how the home was originally designed and built. All of the moisture readings that are taken are recorded on full elevation photos of the home in our proprietary software in the location that they were taken from, providing a "map" of the moisture found in the home at the time of the inspection. We will then help you to understand the relationship between all of the readings. Other useful information is also gathered, such as is the substrate soft, is there any decay present, or is the area tested dry and firm, all of which is useful information.  All of the holes are then subject to our proprietary cleaning process and are filled with a professional sealant that closely matches to the color of your stucco. 

If we are able to gain access to the interior of the building to evaluate areas that have evidence of moisture intrusion (e.g. leaky windows, water staining) and check the attic and/or basement, it does allow us to be more thorough in our inspection, as we are often able to learn more about how the system is performing and also take note of signs of moisture intrusion, staple patterns and other details at this time. 

All of the information we gather during an inspection, including elevation photos with moisture readings, detail photos with specific deficiencies, a summary checklist, condition assessments, and recommendations for next steps are pulled together into a custom report.

The biggest question that we are trying to answer with Phase 1 & 2 testing is "is there a problem". Once it is determined that there is an issue with moisture intrusion at a property, additional steps may need to be taken in order to determine the deficiencies that are present in the system that have led to moisture intrusion and also to verify the extent of the associated damage. Depending on what the results of Phase 1 & 2 testing is, and what the goals of the individual client is, additional testing, known as Phase 3 testing or Destructive Testing, may need to be completed. This is where portions of the stucco/cladding are cut out and removed in order for an inspector to see the flashing and construction details, as well as potential damage and any noted construction deficiencies. 

Our goal is to educate our client though the inspection process and we encourage our clients to be present for the inspection so that we can personally answer any questions and address any concerns that they may have.  Please do not hesitate to call us if you should have any pre or post inspection questions.  

What about thermal imaging or non-invasive techniques?  

What is thermal imaging’s role in stucco inspections?

Very Important: A scanner or infrared camera are great tools to help us locate moisture but cannot be used alone. The wet areas must be probed for rot and ACTUAL MOISTURE CONTENT, and then mapped to meet the test protocol. It should also be noted that a thermal imaging camera will not detect damaged areas that are not wet, while invasive probing does allow you to feel the firmness of the structure, or the absence of the structure in cases of extreme rot and decay. Short of removing the entire system, probing is the best method of testing stucco systems. 

Kevin Thompson of The Green Valley Group is a Level II Certified U.S. Thermographer through the Infraspection Institute, as well as certified moisture contractor through MoistureFindIR. Thermal imaging is a great tool that can help us identify where potential problem areas may be within a stucco home, however, infrared cameras are very sensitive to weather conditions and should only be used by those that truly understand the technology and conditions that affect them. If not used properly, they often times produce false images that miss problem areas or indicate problems that may not be present due to external factors. Infrared 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 the moisture content.

As a certified and very knowledgeable inspection company, we may use thermal imaging on inspections, when weather and other conditions support its use, to detect anomalies in a system and to help locate potential problem areas. We then verify our findings by testing those areas using resistance type probe meters to measure the associated moisture.

When you talk about "probe testing the stucco", just how big of holes do you make?

The moisture meter uses two narrow probes that require holes that are about a 1/4 inch in size. This is roughly the diameter of a standard pencil. After testing, all of the holes are subject to our proprietary cleaning process and are filled with a professional sealant that closely matches to the color of your stucco. Because of the texture of the material, the patches are generally not visible. Please remember it may be impossible to match the colors exactly due to weatherization and solar fading of the cladding or stucco. The inspector takes every precaution to make sure that the test holes are sealed to maintain the integrity of the exterior stucco and to preserve the appearance of the home.

If my walls are wet, do I have to remove all of the stucco?

Not necessarily. It depends very much on how wet they are, how long they have been wet, and how much area is affected, as well as what deficiencies are present within the system that caused the area to get wet. 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 test probe moisture measurements, destructive testing and other factors will help you to make the final decision as to the full scope of repairs.

Can I paint my stucco?

Stucco can be painted. Portland cement-based paints are very compatible with stucco because they are made of the same material. These paints should be scrubbed into the surface and fully cured. Alternatively, you could consider a colored stucco finish. These finish coats are often made with white cement and pigments, providing the widest range of colors. Premixed materials are color matched from batch to batch and are most consistent. Additionally, the fact that you are placing a finish coat with a nominal thickness of 1/8 of an inch instead of a paint layer usually gives more assurance of complete coverage. It is possible to paint with other types of paint, though these are usually not as long lasting as cement-based paint. Acrylic paints are long lasting and durable but change the permeability of the stucco (make it non-breathable) which in some climates may have adverse effects on the long-term performance of the system. We recommend contacting a painting professional for additional information.

Can stucco be cleaned, and if so, what methods should be used? 

Whether you have some type of atmospheric contamination, biological growth, or staining from another construction process, stucco can be cleaned effectively. Because it is important to choose an appropriate cleaning method based on what actually created the stain, there is no single best process for cleaning stucco surfaces.

To clean a dirt-contaminated surface, the following advice is useful: Like concrete and masonry, stucco is porous, and cleaning methods are similar. It is recommended to wet the substrate starting from the bottom and working towards the top. Pre-wetting the surface helps the wall shed water, preventing dirty water from being drawn into dry pores. It also begins to loosen soil so that it can be rinsed away. A garden hose may be effective. Special fan-type sprayers are available for increased cleaning power. Whenever using water on a cement-based material like stucco, the substrate should have set and hardened. Water under pressure can etch the surface and at higher pressures can even cut through hardened stucco. To prevent this, the water spray should be moved over the surface uniformly.

Most dirt is removed fairly easily. Cleaning power is increased by doing one or more of the following: Increasing water temperature, scrubbing with a brush, or using some type of chemical detergent. You should always test the method on an inconspicuous area to first demonstrate its effectiveness and to assure that it won't damage the plaster. To clean stains other than simple soiled surfaces, we recommend contacting a pressure washing professional for additional information.

Prior to the start of any stucco or exterior cladding inspection, The Green Valley Group requires a signed copy of our Building Envelope Inspection Agreement. In the case of a real estate transaction, we require signatures by BOTH the sellers and the buyers.

Probe Holes for Test
Repair of Probe Holes
HomeGauge Home Inspection
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Please Note:

Prior to the start of any stucco or exterior cladding inspection, The Green Valley Group requires a signed copy of our Building Envelope Inspection Agreement. In the case of a real estate transaction, we require signatures by BOTH the sellers and the buyers.

What is The Green Valley Group's stucco testing process?

The Green Valley Group takes a phased approach to testing for moisture intrusion issues with stucco. Our stucco inspections consist of Phase 1 and Phase 2 testing, which is completed within one onsite appointment, and the deliverable is a custom report detailing our findings.

Contact Information:

    (610) 347-0620
    PO Box 242

    Unionville, PA 19375

Additional Service Offerings:



The Green Valley Group is a third party provider of stucco & home inspection, thermal imaging and building envelope forensic consulting services. Our goal is to provide thorough and accurate inspection and testing services to all of our clients while educating them throughout the process. An educated consumer is an empowered consumer, and we're passionate about providing our clients with all of the information they need to make an informed decision.Home Inspection Services Whether you're buying or selling a home, or looking to protect your current investment, professional home inspection services performed by The Green Valley Group and our partners will give you peace of mind and can assist you in a fair and smooth transaction. The Green Valley Group offers a variety of in-house and third-party partner provided inspection and testing services. The Green Valley Group provides thorough investigations of the building envelope (Stucco, Stone, EIFS, etc.) in order to uncover hidden problems, the source of those problems, and then provides recommendations that will lead to corrective solutions. We provide services designed to help buyers, sellers and owners navigate the process. The Green Valley Group provides thermal imaging for a variety of applications. Infrared Thermography can be used to evaluate and find anomalies in exterior cladding (stucco) and mechanical/electrical systems, for noninvasive moisture detection, for leak detection on flat roofs, to identify missing insulation in a wall cavity and even for equine thermal imaging. Our inspection and testing programs have been designed to assure a thorough and easy to understand overview of the conditions of a home. As an independent third-party provider of these services, The Green Valley Group commits to helping our clients navigate buying, selling or home ownership with objectivity and professionalism, and to always keep our clients' best interests at heart.

Our Specialty Areas:​

Stucco & Home Inspection, Thermal Imaging and

Building Envelope Forensic Consulting Services

Stucco & Building Envelope Inspections

The Green Valley Group is a premier independent third party stucco and building envelope inspection company located in beautiful Unionville, Pennsylvania, and our regular service area includes Chester, Berks, Montgomery, Delaware, Lancaster Counties, as well as New Castle County, Delaware.

What is Stucco?

The term "stucco" is used to describe a type of exterior plaster applied as a two- or three-part coating directly onto masonry, or applied over wood or metal lath to a log or wood frame structure. Stucco is a material made of an aggregate, a binder, and water. Stucco is applied wet and hardens to a very dense solid. Stucco is valued as a siding material for its attractiveness and durability and is a relatively low-maintenance (not maintenance free) exterior finish.

What are the issues we are facing with stucco today?

Although stucco systems have been in use for many decades, in recent years it has become popular to place these systems over wood sheathing and studs. These systems can be well designed, but unfortunately they rely upon installation details that are completely concealed after the system is completed. The most important part of the stucco cladding system is the moisture barrier and flashing system. We are finding many homes built in the last couple decades that have severe water damage are due to poor detailing by the original installers. Many of these issues go unforeseen by the home owner because they are concealed within the wall cavity. It's not until professional testing is performed that these hidden issues are discovered. Some issues, if caught early enough, do not require removal of the stucco, however, often times large wall surfaces need to be opened or completely removed to make the correct repairs. The most drastic cases are entire home tear offs.

How can I tell if water is building up in my walls?

Most times, you can’t. It is only with a comprehensive professional moisture intrusion inspection that we can 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 stucco and directly measuring the moisture content of the building materials inside. An intrusive probe is required for the determination of specific moisture content. The level of moisture content of the homes substrate, including recent weather conditions, leads us to how we need to address the issues.