The Top 10 Construction Defects Observed Across the U.S. in 2018

March 12, 2019 in Tech Alert

By: Jeff Hoch, Principal Architect

Quality Built, LLC (QB) is the nation’s leader in third-party QA inspections and risk management solutions for new building construction. Our Field Consultants average over 20 years’ experience in the industry and comprise of architects, engineers and licensed inspectors. In 2018, Quality Built collected data on nearly two million (2,000,000) data points via our proprietary QB Builder Link® app on thousands of projects across the United States. As a result of our inspections, we identify positive and negative trends while educating the industry on methods to address construction risk and remediate anomalies.

In this Tech Alert article, we will be uncovering the top ten most common issues observed during our inspections performed across the U.S. in 2018. The following anomalies are listed in order of construction sequence and not by the frequency in which these failures were identified. Post construction repair costs are rough estimates and reflect nationwide averages. With an average cost of $650 per home for a full-scope/comprehensive QA inspection, builders often experience an ROI of eight times their investment while avoiding the many consequences of poor building practices.

1. Foundation - Vapor Retarder

Slab or crawlspace/basement moisture intrusion has been a long-standing issue for builders nationwide. In 2018, we observed anomalies with the vapor barrier at 65% of the data points collected for this item.

Moisture intrusion through the slab can cause damage to flooring and contribute to poor indoor air quality when moisture is present under areas such as cabinets. Furthermore, moisture intrusion in crawlspaces can result in bio-organic growth and indoor air quality issues. In severe cases, exposed structural framing in the crawlspace can be compromised.

All seams and penetrations must be sealed with the proper materials and under the appropriate conditions to meet the requirements of regional building codes and manufacturers’ specifications. Any damage to the membrane must be repaired to effectively retard the moisture vapor transmission.

Repairs using a topical vapor barrier costs approximately $2.00 per square foot, which includes product and labor. This does not include the disposal and replacement of any damaged flooring, cabinets or other items.

2. Framing - Trusses Bearing on Non-Bearing Walls or Incorrectly Attached

While we saw a variety of anomalies related to framing on the projects we inspected in 2018, those linked to trusses bearing on non-bearing walls or were incorrectly attached were the most prominent issues that were identified nationwide.

The consequences of these issues often result in drywall cracking, and unpleasant audible popping noises as the trusses deflect the underload and shift. Movement can also be caused by expansion and contraction of the truss members or the wall framing. These conditions result in homeowner complaints and claims.

Overdriven fasteners at shear or braced wall assemblies stood out as the next most frequently observed anomaly linked to framing. The problem with overdriven fasteners is they reduce the load that the assembly can resist without failure. While these walls are designed to prevent or reduce structural damage during an earthquake or high winds, the loss of load resistance can result in injuries or fatalities.

Repairs for trusses bearing on non-bearing walls can run $50 per lineal foot, which includes removing drywall, double top plate and patching. The expense to remediate incorrect attachments is significantly less, depending on the level of access.

3. Fire Blocking - Missing or Damaged

Fire blocking is installed to reduce the spread of fire, particularly from vertical spaces to horizontal spaces and vice versa. Not understanding the requirements or purpose of fire blocking results in the failure to install it at all required locations. Additionally, not understanding the purpose results in the fire blocking being damaged by later trades who often knock it out to run their plumbing, electrical, or mechanical through the area. The risk is that in the event of a fire, the lack of fire blocking can allow the fire to spread more rapidly and reduce the time the occupants have to evacuate the building, resulting in injuries and fatalities.

Repairs can only be reasonably accomplished before the drywall is installed, otherwise the condition would be difficult to locate.  Repairs cost about $500 per location, which includes repainting the entire wall plane. 

4. Insulation - Not Properly Lofted (Lacking 6-sided Contact)

As energy requirements are increasing, we are seeing a rise in defects and claims related to the performance of buildings. Real Estate Due Diligence inspectors utilize infrared cameras to advise purchasers of anomalies in the insulation and associated energy loss. On projects where we are inspecting the insulation, we found insulation installation anomalies at 90+% of the units inspected in 2018.

The risk of claims related to improper installation of insulation will increase as the energy codes continue to become stricter and more jurisdictions are requiring energy-related testing of buildings.

Repairs can cost close to $100 per square foot, which includes the infrared inspection needed to determine locations requiring repair and the removal and replacement of drywall to allow access.

5. Windows - Installation

Window installation deficiencies are continually observed in building construction. Even trade partners who consistently perform quality window installations will, on occasion, have a window installed improperly as a result of window transportation and storing, sealing, fastening, flashing, or issues associated with framing.

Transportation and storing issues can result in bent or broken window fins and/or jambs, frame distortion, damaged glass, screen damage, and locking mechanism damage.  Sealing issues include incompatible sealant products, gaps in applied sealant, improper location of sealant, and opening sizes not allowing the sealant to contact surfaces properly.

Fastening issues include improper fastener types, fasteners located too close to window corners, over and under-driven fasteners, improper fastener spacing, and fasteners driven through fins and jambs in locations that are not recommended by the window manufacturer.

Common flashing issues include incompatible flashing materials, improper sequencing or lapping of flashings, flashing material installed with folds or wrinkles, and gaps in the window flashing system typically in the lower corners.

Improperly installed or damaged windows can account for significant moisture and air infiltration into the building envelope - making this an extremely important construction element to properly install. One of the largest causes of construction defect litigation is leaks through windows or building walls when these installations do not perform as expected.

Further discussion and installation information on windows can be found in the following Quality Built Tech Alerts:

The Ever-Evolving Building Envelope:

The Size of the Window Opening Determines the Size of the Risk

The cost to repair these types of window-related anomalies depends on if the leak is linked to flashings or to the window product, as well as the difficulty of isolating the leak location. The more difficult the leak is to locate, the more of the wall that will need to be opened to repair the flashings. If the window product is defective and cannot be fixed in-situ, then the cost will be higher. Expenses can be as low as several hundred and range up to several thousand dollars.

6. Exterior Walls Weatherization - QuickFlash Improper Use or Integration

The use of QuickFlash flashing panels to flash exterior wall penetrations is increasing, and, in turn, has resulted in an increase in the number of defective installations. In 2018, 70% of the nearly 13,000 QuickFlash flashing installations that were inspected contained anomalies.

Failure to use the proper QuickFlash flashing for penetrating items not only voids the warranty but creates a risk of water intrusion as the panel will not properly seal to the penetrating item.

Risk of water intrusion is common amongst all weather-resistive barriers (WRB) but particularly with the housewrap and sheathing-based WRBs that require tape flashing to seal the panel to the WRB.

Common issues include failure to bibb the bottom of the flashing or terminate the bottom over the WRB in a weatherboard manner. One major issue is that the tape flashing used to integrate particularly with sheathing-based WRBs is not properly sealed, creating bird-mouths that can result in water intrusion.

Repairing these issues would involve removing stucco, properly integrating the QuickFlash and patching the stucco, amounting to approximately $750. The size of the wall, and the need for paint or fog coating would also affect the cost of the repair.

7. Exterior Walls Weatherization - Holes, Rips, or Tears in WRB

The use of traditional asphalt-impregnated building paper is becoming less common in the industry. Housewraps, sheathing-based WRBs and other water/weather resistive barriers are becoming more and more popular. During our inspections, we have found many of the same defects we would see with traditional asphalt building paper, as well as some new variations.

One of the ongoing issues we have seen is failure to properly treat penetrations. While many builders are specifying the use of flashing panels such as QuickFlash, not all penetrations can be treated using these panels. Additionally, the panels are often improperly installed as discussed in the section above. Failure to properly seal the penetrations and treat the holes in the building envelope can result in water intrusion.

The next most common issue we continue to see is the improper approach at remediating damage to the WRB. Holes, rips and tears in the WRB must be repaired or sealed to maintain the water resistance of the membrane.

Some new WRB systems have presented an issue with seam tapes creating reverse laps, which if not installed correctly can result in water intrusion. These products are also able to serve as an air barrier. In these cases, improper seam sealing can result in air leakage affecting the performance of the air barrier.

Water intrusion into a home can result in significant issues for the builder and the homeowner, including damage to building materials and the occupant’s possessions, as well as potential health concerns. Additionally, the risk for claims resulting from air infiltration is increasing as stricter codes are going into place for energy efficiency requirements. For more information related to the building envelope, refer to our “Flashing Panels for Exterior Wall Penetrations” Tech Alert and “The Ever-Evolving Building Envelope” series listed in section five above.

The cost to repair these issues will vary depending on the difficulty of isolating the leak location. The more difficult, the more of the wall that will need to be opened to repair the WRB. Cost can be as low as several hundred and range up to several thousand dollars.

8. Roofing - Flashings

The requirements for roof flashings, roof felt, and other roof assemblies all require installations to be done in a “weatherboard fashion”. Each of the above are very important segments vital to roof performance. It is not uncommon for us to observe various roofing products being installed incorrectly. The most common anomalies observed in 2018 included improper laps of materials not meeting the code or manufacturer’s requirements and reverse laps at penetration flashings improperly installed without a bibb.

Some of the specific conditions noted include:

  • Roof mastic used in place of correctly installed flashings.
  • Roof eave drip edges installed over the roofing felt instead of under it. Conversely, where Florida code requires the roof eave drip edge to be installed over the roofing felt to prevent the wind from catching the felt, we often find it installed inverted.
  • Roof jacks that are not correctly bibbed (woven) into the roof underlayment in a weatherboard fashion, again, relying on mastic as a final seal. This is common in asphalt shingle installations in some regions where the sequencing has the flashings being installed after the shingles are installed rather than at the same time.
  • Holes and rips in roof underlayment, repaired with mastic instead of a bibb of felt from the next highest seam.
  • Closed rake kick-outs either not installed at all or installed incorrectly.

Roofing mastic is a great product when used in the proper applications and when properly installed; however, we often see it used inappropriately. Roofing mastic has a service life that is less than properly installed flashings, roofing felts, and roof claddings and requires regular inspection and maintenance (which many owners fail to perform).  The risk associated with these anomalies is that water intrusion will likely occur causing damage. Roof leaks are typically more noticeable and impactful than window leaks. As a result, they will invariably result in customer complaints and increased risk of defect litigation.

Repair costs will depend on the type and extent of the defect; however, most repairs will result in a minimum of $250 and may be as high as several thousand dollars.

9. Exterior Cladding - Stucco

In many regions of the country, exterior cement plaster (aka stucco) is a common exterior cladding. The most common defects observed in 2018 related to stucco included the mixing, lathing, and application of the stucco.

The risks range from minor and major cracks to large scale efflorescence to soft stucco. Incorrect lath installation can result in cracking, especially when the stucco mix is improper and/or there is insufficient hydration of the fresh stucco. Improper mix ratios and hydration can also result in large scale efflorescence and/or soft stucco. While some of these issues may be more cosmetic in nature, they often result in homeowner complaints and help to fuel construction defect claims cases.

While many of the cracks we have forensically investigated had several contributing factors, the majority had one factor in common - improperly embedded lath. Improper lath installation was noted at 75% of the locations inspected by our Field Consultants in 2018.

Repair costs will vary depending on the cause of the cracking, ranging from $1 per square foot of affected wall plane to $14 per square foot.

10. Failure to Follow and/or Incomplete Plans, SOW, Product Specifications

Technical Plan Reviews (TPR), and Geotechnical Design Reviews (GDR) should be a fundamental practice to ensure proper integration of materials and coordination of design professionals. Based on our experience, we recommend reviews at the design stage (30% completion) and again at 80 to 90% completion.

As part of our Geotechnical Review, we often report an apparent disconnect between the Geotechnical Engineer of Record, other professionals, the client, and the builder, which leads to incorrect recommendations reported on construction plans.

Failure to follow the plans, specifications, or manufacturer’s recommendations generates risks. Incorrectly installed items often void the warranty and make obtaining insurance dollars to help cover repairs more difficult. Incomplete plans and plans with incorrect information can result in faulty construction, and eventual failures. This risk can be limited and/or reduced if a TPR and GDR are performed, and plans are reviewed prior to finalization. Failure of the trades to follow their Scope of Work (SOW), the plans, and/or the specifications can result in incorrectly installed products or systems creating risk that escalates from a cosmetic issue to a potential structural failure that could result in injuries or fatalities. To reduce these risks, an active QA/quality control (QC) program is necessary to catch and correct issues as they arise during construction.


To discover and report/remediate the above issues, builders have found it necessary to employ third-party inspectors to provide an additional level of on-site supervision to the ever-changing installation practices beyond what their own field managers and local city inspectors are providing. This is not to say the local inspectors aren’t doing their job, it’s better said: today’s construction practices demand a higher frequency of inspections with a greater depth of scrutiny well beyond just inspecting for broader code compliance.

To bring a higher level of inspection, education and observation to the job-site, skilled inspectors are needed to focus on the most common areas of installation mistakes. Since Quality Built has a vast wealth of data from the thousands of inspections we have performed, we know what to look for and have the ability to find the issues that continue to plague builders.

An effective QA program starts at the plan stage, well before construction begins, with a detailed review of the plans. Not leaving the obvious to chance, Quality Built strongly suggests that plan details include clear diagrams and written directions for all of the issues that commonly fail. Once construction begins, an inspection by an independent third-party inspector helps to verify the trades are following the plans, code, manufacturer’s requirements, and industry best practices. Let’s work together as an industry to help minimize and eliminate the top 10 defects observed in 2018.

About the Author

Jeff Hoch, Principal Architect

Jeff is a licensed architect and has been involved in the construction industry for over 27 years. He has a passion for safety and strives to educate the industry about building best practices and risk mitigation techniques. Jeff is constantly taking part in educational seminars and is extremely knowledgeable when it comes to building code requirements. Jeff performs inspections across the nation and specializes in forensic inspections, AAMA/ASTM water testing, technical peer plan reviews, quality assurance, and much more. He also is extremely experienced with design standards, local ordinances, forensic building failure analysis, and construction defects. You can reach Jeff at [email protected].

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