Penetration Coordination at a Mechanical Louver
You are inspecting a large mechanical louver penetration through an EIFS wall on a mid-rise building. The louver frame is set with a 3/4 in. (19 mm) gap to the rough opening, and the gap is filled with expanding foam that has been trimmed flush. The WRB terminates at the rough opening edge without being turned into the opening or sealed to the louver frame. The louver has a head flange but no sill flashing, and the EIFS finish returns into the opening and stops against the louver frame with a bead of sealant. The mechanical contractor says the louver is 'rain-resistant' and the foam seals the gap. The specification requires the WRB to be integrated with the penetration and a flashed sill at all openings.
1. Assess the WRB termination and the foam-filled gap at the louver.
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The WRB termination is deficient. The WRB must be integrated with the penetration, typically by turning it into the rough opening and sealing it to the louver frame or to flashing, so that water reaching the WRB is directed to the exterior rather than into the wall cavity. Simply terminating the WRB at the opening edge leaves an unsealed path around the louver. The expanding foam does not substitute for this integration: foam is not a WRB, it can shrink or crack, and it does not provide a continuous drainage path. The 'rain-resistant' louver claim addresses the louver's own performance, not the wall's water management. Require the WRB to be turned in and sealed to the frame or flashing, and require a proper flashed sill at the opening. Document the condition and re-inspect after correction, before the finish is closed in.
2. What is your finding on the missing sill flashing and the sealant-only return?
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Both are nonconforming. Every opening, including a mechanical louver, needs a flashed sill to collect and discharge water that gets behind the louver; a head flange alone does not manage water at the bottom of the opening. The EIFS finish returning into the opening and stopping against the frame with a sealant bead is not a substitute for flashing and proper joint detailing. The joint should be constructed with a backer rod and a sealant compatible with both the EIFS and the louver frame, and the sill should have flashing that laps into the WRB and discharges to the exterior. Require installation of sill flashing integrated with the WRB and rework of the perimeter joint to the specified sealant detail, then re-inspect the entire penetration before sign-off.