EIFS Inspection Procedures & Quality Control 3 — Questions and Answers
Question 1: During an EIFS inspection, an inspector uses a probe penetration instrument on a suspect area and reads 22% WME. What does this most likely indicate?
- Normal moisture equilibrium within acceptable limits
- Elevated moisture that warrants further investigation or destructive testing (Correct answer)
- Dry conditions confirming no water infiltration
- High ambient humidity affecting the reading only
Correct answer: Elevated moisture that warrants further investigation or destructive testing
A WME reading of 22% is elevated and suggests potential moisture accumulation behind the EIFS, warranting additional evaluation such as core sampling.
Question 2: What is the primary purpose of the 'backwrap' detail in EIFS installation?
- To provide additional insulation at the wall base
- To terminate the mesh and lamina cleanly and weatherproof at system edges (Correct answer)
- To improve the aesthetic finish at penetrations
- To create a thermal break at structural steel
Correct answer: To terminate the mesh and lamina cleanly and weatherproof at system edges
Backwrapping folds the mesh and base coat around the EPS board edge, sealing the termination to prevent moisture intrusion at system edges.
Question 3: An inspector finds that EPS board joints were staggered at horizontal courses but were aligned at a window corner. What deficiency does this represent?
- Only an aesthetic concern with no structural impact
- A stress concentration point that can lead to diagonal cracking at the corner (Correct answer)
- Improper color matching at the joint location
- A thermal performance deficiency only
Correct answer: A stress concentration point that can lead to diagonal cracking at the corner
EPS joints aligned at window corners create stress concentration points where diagonal cracking often initiates; boards must be cut so joints do not land at corners.
Question 4: Which condition is considered a critical deficiency requiring immediate remediation in a drainage-type EIFS system?
- Minor surface crazing less than 1/32 inch wide
- Blocked weep screed preventing moisture drainage at the base (Correct answer)
- Slight texture variation in the finish coat
- Color fade from UV exposure over 10 years
Correct answer: Blocked weep screed preventing moisture drainage at the base
A blocked weep screed prevents moisture from draining out of the drainage cavity, defeating the drainage system's purpose and risking structural damage.
Question 5: Under ASTM E2570, what parameter is evaluated during a water-resistive barrier inspection for EIFS?
- Fire resistance of the WRB membrane
- Water penetration resistance of the WRB over simulated openings (Correct answer)
- Thermal conductivity of the WRB layer
- Impact resistance of the installed WRB
Correct answer: Water penetration resistance of the WRB over simulated openings
ASTM E2570 evaluates the water resistance of WRBs used with EIFS by applying water at specified pressure over test openings to detect leakage.
Question 6: When reviewing quality control records for an EIFS project, which documentation is most critical to verify material conformance?
- Subcontractor insurance certificates
- Manufacturer's product data sheets and batch delivery receipts (Correct answer)
- Building owner's approval sign-off forms
- Architect's field observation reports only
Correct answer: Manufacturer's product data sheets and batch delivery receipts
Product data sheets confirm specified materials were used, and batch delivery receipts verify that materials came from the approved manufacturer's production run.
Question 7: An inspector observes that the EIFS contractor did not install a kick-out (diverter) flashing where a roof slope meets a sidewall. What is the risk?
- Condensation will form inside the wall cavity only
- Roof runoff will be directed behind the EIFS causing chronic water intrusion (Correct answer)
- The roof shingles will lift at the eave due to back-pressure
- Only aesthetic staining of the finish coat will result
Correct answer: Roof runoff will be directed behind the EIFS causing chronic water intrusion
Without a kick-out flashing, roof drainage runs down behind the cladding at the roof-to-wall junction, introducing large volumes of water into the wall assembly.
EIFS Inspection Procedures & Quality Control 3
During an EIFS inspection, an inspector uses a probe penetration instrument on a suspect area and reads 22% WME.
What does this most likely indicate?