I have a 20-yr old home. Construction is EFIS over metal studs. I'm planning on removing EFIS and replacing with conventional plywood, TYVEK, Paper, Lath and Stucco.
Many holes in EFIS system, the latest were from the previous owner's shoddy installation of shutter track without using a urethane sealant for screws. However, lower 2 ft of stud oxidation indicates problems may pre-date this snafu. Moisture readings from between drywall and EFIS range from 40% to 90%.
Contractor indicated he can cut and replace lower rusted portion of studs and bottom channel. Two questions:
1. Would you recommend installing tar paper under the bottom channel to electrically isolate the slab from the studs.
2. Would you recommend connecting the metal framing to a buried sacrificial cathode? Any idea on what this would cost?