Common Mistakes Found During QA Inspections on New Construction

(QA) is a proactive management process

According to research from the Get it Right Initiative (GIRI), anywhere from 10-25% of construction costs are caused by errors.

The initiative suggested that most of these errors are formed in the planning phase and outlined new management processes and oversight as a solution to many of these problems.

While many construction managers rely heavily on quality control mechanisms to correct final product errors, quality assurance management (QA) provides a more affordable and proactive solution to many of these problems.

Unlike QC specialists, QA managers provide step-by-step oversight of the construction process to ensure that projects are finished on time and to target specifications.

With that said, we’d like to outline some of the most common construction mistakes we found after doing dozens of inspections on new buildings.

What Is Construction Quality Assurance?

Construction quality assurance (QA) is a proactive management process designed to supervise construction managers through each step of the construction phase to ensure that projects meet their target criteria.

The primary difference between quality assurance vs. quality control is that quality assurance is conducted through each step of the construction process and not just on the final product.

Having this proactive oversight over your construction process can help you mitigate errors, reduce costs, and ensure you meet your target specifications.

What Are the Benefits of Quality Assurance?

  • Reduces costs associated with construction errors
  • Ensures a pristine final product
  • Reduces the need or cost for quality control fixes
  • Provides proactive advice on cost-savings measures, including proper insulation techniques or energy-efficient building materials
  • Improves customer satisfaction by ensuring projects are built on time and to spec
  • Allows you to plan for mistakes rather than spend the bulk of your time fixing them

Common QA Mistakes to Avoid: Step-by-Step

With these QA benefits in mind, let’s run through some common QA mistakes you should be aware of, so you can start planning to prevent these errors in your construction projection. Reviewing these errors step-by-step will allow you to create plans to avoid these costly errors during the planning phase.


Laying the foundation or slab is the first step of the actual construction process. Some of the most common mistakes we find during the foundation laying are:

  • Pouring over loose soil
  • Pouring an uneven slab
  • Curing too quickly

As a result, many warning signs may surface as the foundation begins to settle later on in the construction process, including:

  • An uneven foundation
  • Cracks forming in the foundation
  • Gaps forming between walls and doors or windows

Planning for these issues, including when soil shifts or becomes too moist from rain during the construction process is paramount to the success and integrity of your finished product.


Framing can be subject to many more errors due to the number of human hands and manual labor involved in erecting a home’s frame. Some of the most common errors in home framing include:

  • Using the wrong framing nails (e.g., not using ACQ-approved nails)
  • Overdriving fasteners into panels and other framing members
  • Using narrow walls by large openings in the home’s frame
  • Installing sheathing over a single span
  • Installing Glulam beams upside down
  • Improperly spacing panels, which are not installed properly on the strength axis
  • Consistent deflections formed by overly spaced floor joists
  • Floor squeaks from improper gluing
  • Not accounting for steps when laying your floors
  • Not checking for stud crowns

Unfortunately, framing issues can lead to sagging and squeaky floors, as well as costly structural issues that put homeowners at risk.

It’s helpful to have a QA specialist on hand when mocking up your frame to avoid these mistakes.

House Wrap

House wrap is another important consideration that can easily be overlooked during the building phase. For example, using cheap wrapping material or leaving windows exposed can allow moisture to build up, which can cause problems for the framing and foundation.

Some of the most common wrapping mistakes include:

  • Not using capped fasteners
  • Using cheap wrap paper
  • Not giving enough overlap in the wrap
  • Improper window installation or lack of cover


With the advancement of spray foam insulation and various other materials, the ability to insulate home spaces and conserve energy has never been greater. Between thermal inspections and prescribing best practices, a QA specialist can help you avoid and identify the following mistakes in your insulation:

  • Covering eave vents
  • Failing to insulate attic floors
  • Using cheap materials, such as fiberglass batt insulation
  • Not using non-IC-rated recessed fittings where lots of air escapes
  • Not properly sealing knee walls
  • Not sealing rim joists

Energy Equipment Installation

Home appliances can be another source of error for many builders and be costly to fix. Here are some problems commonly associated with HVAC, plumbing, and electrical installation.

  • Improperly vented HVAC equipment
  • Insufficient access to above-ceiling components
  • Overtightened plumbing connections
  • Improperly sloped shower flooring
  • Damaged duct vapor barrier
  • Non-continuous duct insulation
  • Unsecured wires
  • Improper wire lengths and connections

Not only can a QA expert help you avoid these errors, but they can also prescribe equipment that is available for rebates and tax credits to save your crew money.

Drywall/Interior/Exterior Finishing

Drywall, roofing, and siding can be another massive source of frustration for home builders and lead to costly mistakes. Here are some of the most common mistakes that QA specialists can help builders handle:

  • Mismatching shingles
  • Framing drywall on inside corners
  • Fastening an unfitted drywall
  • Nailing siding too tight
  • Using short-length nails for siding
  • Using improper roofing nails
  • Using improperly sizes shingles for roof eaves

Final QA Inspection

Once the house is built and ready for inspection, your QA consultant may run their own final QA walkthrough as a preliminary for quality control testing. Generally, they will uncover a lot of the same errors that a QC inspector might and allow you time to resolve those errors before development goes any further.

Due to the sheer complexity of most construction projects and their vulnerability to mistakes, it usually pays off to work with a qualified QA specialist to plan for any mistakes. Not only will a QA expert help you proactively avoid costly errors, but they can teach you best practices that you can use with you on future job sites and to train your crews.

QA experts can provide safety training and help you develop a stormwater management plan to ensure your construction project complies with regulations and is safe for everyone involved.