Building inspections and building envelope evaluations – analyzing the building’s masonry, granite, EFIS, glass, and insulated wall panels are among the most critical but most often overlooked ways a building envelope evaluation expert can help prevent costly damage.
Whether your property is used for commercial purposes, education, or healthcare, a building inspection and envelope evaluation is critical, especially if the building contains critical interior spaces or houses expensive equipment.
Regardless of the type of building, the building envelope including the roof, walls, windows, and structure should be tested at a minimum of every 5 years to be certain that it is water-tight, energy efficient, and safe from damage caused by storms and tornadoes.
While most building owners have the roof inspected periodically, many often forget about the rest of the building envelope. After a building inspection, building owners are often surprised when the results of the inspection show loss of energy through windows, gaps around doors, or holes, or penetrations in the building envelope that should be patched or re-sealed.
In addition to energy inefficiencies, these same problems can contribute to water or moisture penetration into the building. Some of the moisture can be seen, but even more could remain unseen. Water intrusion can lead to significant exterior wall damage, including structural failure, damaged floors, and mold growing on the inside surfaces of gypsum drywall.
What Is the Difference Between a Building Inspection and a Building Envelope Evaluation?
If you are considering a building envelope analysis, CTL Engineering offers a full range of diagnostic and design services in all facets of the building envelope, including roof systems, wall systems, and waterproofing. Depending on your needs, you might consider a building inspection or a building evaluation.
- Building Inspection. A building inspection is an in-depth analysis by a building envelope evaluation expert that uses information taken from a visual-only survey to determine whether and where a more serious assessment should be performed on particular places of the building’s skin.
- Building Evaluation. A building evaluation is performed based on the results of a building inspection. For example, if you suspect there is no “end dam” at building flashings in the walls, or that there are no masonry tiles to connect the face brick to the inner wall, a building evaluation would be appropriate. A building evaluation is more in-depth and might involve a more destructive evaluation than a building inspection.
Building Envelope Analysis Can Uncover Hidden Structural Problems and Prevent Expensive Damage
A building survey is a useful tool for identifying potential problems with the building envelope. However, a visual inspection might identify a symptom, but not the underlying cause or precise location of the underlying problem. Visible leaks, for example, often fail to reveal the location of the underlying problem. In some cases, a leaky roof is actually caused by a defect in a wall.
Likewise, in many cases, minor repairs can cover up or even exacerbate an existing problem. Replacing a cracked brick on a building’s exterior might address surface damage but not the root cause.
CTL Engineering was recently asked to replace an older roof on a building that had a new single ply membrane roof that had been leaking. CTL Engineering conducted a building envelope evaluation and discovered the beginnings of significant brick failure due to spalling (the first ¼“ of the brick face falling off). Further investigation revealed:
- The control joints had lost their sealant and were allowing water to penetrate the wall cavity
- The sealant around the aluminum windows had started to fail, allowing water to penetrate the building
- Someone noticed water weeping out of the “hole” in the mortar joints and sealed every hole around the entire building.
The weep holes, however, were intended to allow any water that entered the wall cavity to weep out. Covering them up created a backup of water that found its way into the brick masonry and froze during the winter months, causing the brick face to spall and fall off. In this case, the building envelope evaluation revealed hidden structural problems which, if left untreated, could have caused extensive damage.
What’s Involved in Building Envelope Evaluations?
To perform a building envelope evaluation, CTL Engineering begins by researching the building’s history and conducts a field inspection, evaluation, survey, testing, and laboratory analysis using specialized equipment and our experience.
CTL Engineering does not just inspect the individual parts of the building envelope we also analyze how these distinct parts function together. Different wings of buildings, for example, may have been constructed at different times, using different materials. Nevertheless, these individual parts must function as a whole. CTL Engineering analyzes the building envelope holistically and makes recommendations to prevent expensive damage.
CTL Engineering has the experience and equipment to perform the following tests:
- RILEM Tube Test. A test to assess masonry walls resistance to water absorption, condition of the brick, mortar joints, head joints, and embedment joints.
- AAMA 502 / ASTM E1105 Window Water Infiltration Test. A test that simulates a wind-driven rain condition at a facility to determine a specific cause and origin of moisture infiltration.
- AAMA 501.2 Window Spray Test. A test method that simulates wind-driven rain in a small segmented area – spraying a specific crack, joint, or defect to uncover potential moisture infiltration.
- ASTM E783 Air Leakage Test. A pressure chamber constructed at a specific location on the interior of the facility to test moisture driven through an assembly or component.
- Infrared Thermography / Scanning. The Fluke Thermal Imager Ti45 Infrared Camera and Delmhorst BD-2100 Moisture Meter are used to detect possible areas of missing or displaced insulation, or voids within control or expansion joints and sealants in exterior wall areas.
- Concrete Sound Test. A hollow sound indicates areas where concrete may have separated from steel reinforcements, often due to exfoliation or corrosion of the steel.
- Pachometer Survey. A test that uses a magnetic device to locate hidden steel in concrete.
- Polysheet Tapedown. A test used to determine the presence of moisture coming through a surface. A 2’ x 2’ section of polyethylene over calcium chloride is sealed to the concrete with duct tape and removed 24 hours later. Moisture beneath the polyethylene is a good indicator that there is a vapor drive through the concrete section.
- Glass-Slide Epoxy or Crackometer. A device sealed over a crack and periodically checked to determine whether any movement has occurred. If movement does occur, the glass will break, or the meter will record movement.
- Optical Illuminated Boroscope. A boroscope is inserted into a ⅝” diameter pilot hole drilled through an exterior wall, allowing the cavity walls of brick veneer, stud wall backup of exterior insulated finish systems (EIFS), or other types of constructions to be observed without large-scale destructive testing.
- Smoke / Dust Tracer. A simple test that helps find air infiltration. The tracer is moved across the interior face of a window to observe the smoke and dust particles coming through the assembly.
- Moisture Meter. A digital device used to detect the presence of moisture in building components, usually on flooring.
CTL Engineering provides various levels of condition assessment to assist our clients in managing facility assets.
Our roofing and building envelope evaluation cover both the interior and exterior of the building, and we routinely obtain non-destructive samples that we analyze for moisture infiltration using state-of-the-art techniques including infrared, nuclear, and capacitance equipment as part of our diagnostic process.
When the primary objective is to determine the existing composition and configuration of concealed assembly conditions, destructive testing might be necessary.
- Roofs. Test cuts in the roof assembly may be necessary to determine the condition of the underlying insulation and substrate. Cutting into the system will help verify whether roof problems are causing a corroded steel deck, or a spalled and cracked concrete deck. Test cuts also expose the configurations of the flashing components, roof to wall location, and curb locations. This is critical to determine the appropriate remedial design and to specify the appropriate flashing details.
- Exterior Walls. Test cuts on exterior walls are useful in determining the origin of moisture infiltration. For a masonry wall, tests cuts are often made at window heads and sills, and at any through-wall flashing location that are suspected points of moisture infiltration.
CTL Engineering also offers laboratory testing to identify the existing material types used in the construction including the presence of contaminants, and the possibility of hazardous components.
CTL Engineering sends samples of sealants, coatings, fainted finishes, and roofing materials to an independent laboratory to determine the presence of lead or asbestos. Samples of masonry or concrete can also be tested to identify the cause of moisture or air infiltration using:
- A Gravimetric Analysis is a test used to determine moisture content by weighing and recording an existing sample. The sample is compared to a sample that was dried in an oven. The weight difference indicates moisture content, particularly useful in evaluating insulation materials and critical to verify results from non-destructive moisture scans.
- Asbestos and Lead testing of paint, sealants, plasters, and roofing materials can be used to determine whether asbestos or lead was used in a component of the building.
Building Owners Should Perform Building Inspections and Building Envelope Evaluations Regularly
Building exteriors should be visually inspected at a minimum of every five years. Owners should check local government ordinances mandating testing periods for buildings within a defined geographic area, and they may require the owner to file a report of the overall condition. Depending on the results, repairs may need to be completed within a specific timeframe.
While these ordinances might seem onerous to a building owner, they are intended to protect the public who walk or drive by these buildings.
At CTL Engineering, we have the experience, expertise, and equipment to conduct a building envelope analysis to help prevent costly moisture infiltration and improve building safety and efficiency.