Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Communication Breakdown; Time Pressure; Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; MEL
Maintenance placarded potable water in lavatory LX inoperative per MEL. I asked the Maintenance Technician who brought logbook up to cockpit to confirm compliance with correction requiring the entire lavatory be placarded inoperative due to COVID precautions. He said he understood that placarding the sink was sufficient to comply with MEL. My interpretation was different; and out of an abundance of caution I asked him to place a 'lavatory inop' placard on the affected lavatory door. We advised FA A; and did not use that lavatory. During cruise; after additional review of the maintenance text; I contacted Maintenance Control. They confirmed that to comply with the correction; the entire lavatory should have been placarded and requested I make a Logbook entry to that effect before arrival into ZZZ.
Air Carrier Captain reported blocking off the entire lavatory from use due to the potable water in the lavatory being placarded inoperative. Captain decided to block the entire lavatory for COVID-19 precautions.