Mixed Substrate and Sheathing Gaps on a Mid-Rise EIFS Job
You are inspecting a 6-story EIFS-clad building over a steel-stud frame. The sheathing is a mix: exterior gypsum on floors 1-3 and oriented strand board on floors 4-6. The crew is installing the water-resistive barrier (WRB) as they go. You observe that on floors 4-6, several OSB panel joints have visible gaps up to 3/8 in. (9 mm), and the WRB is lapped 2 in. (50 mm) at vertical seams but not taped. On floor 2, a gypsum panel is crushed at a stud location where a screw was overdriven. The general contractor says the EIFS manufacturer's published installation instructions permit the gaps and that the WRB is 'self-sealing.' The project specification requires compliance with the manufacturer's instructions and the applicable code.
1. How do you evaluate the OSB joint gaps and the untaped WRB vertical laps?
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Neither the gap claim nor the 'self-sealing' claim can be accepted on the GC's word. First, pull the actual manufacturer's published installation instructions and the project specification, and compare them against what is installed. Many EIFS systems require sheathing joints to be within a stated tolerance and require the WRB to be continuous and sealed at laps; a 3/8 in. gap may exceed the sheathing manufacturer's edge-spacing tolerance and can telegraph through the lamina or compromise the WRB continuity behind it. Second, the WRB lap must be evaluated against the manufacturer's minimum lap and the code requirement for a continuous drainage plane; 2 in. may be below the required lap for the specific product, and untaped vertical laps create a path for water intrusion behind the EIFS. Document the conditions with measurements, photos, and locations, issue a nonconformance, and require correction per the manufacturer's instructions before the base coat and mesh are applied. If the manufacturer truly permits the condition, obtain written confirmation from the manufacturer's technical representative and attach it to the inspection record.
2. What is your disposition on the crushed gypsum panel at the overdriven screw?
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A crushed or broken sheathing panel at a fastener is a substrate defect that must be corrected, not merely noted. Overdriving the screw has crushed the gypsum core and broken the paper face, which reduces the panel's ability to hold the fastener and can create a localized soft spot that affects the flatness of the EIFS lamina above it. The correct action is to require removal and replacement of the damaged area or the panel, with fasteners reset to the manufacturer's specified depth and pattern, then re-inspect before the WRB and EIFS are installed over it. Record the location, the fastener spacing actually used, and the correction. This is a substrate-verification item: the inspector confirms the sheathing is sound, properly fastened, and within flatness tolerance before covering it up, because once the EIFS is closed in, the defect is inaccessible.