The bathroom was renovated it 1 years ago and was painted using Regal Paint from Benjamin Moore. The painter was supposed to use a special bathroom paint from BM " Aura Bath Paint since our bathroom does not a window- we installed a sky light and the strongest fan inside. We found out later he did not use the Aura Paint. I noticed there were some blistering paint outside the shower wall ( plumbing was the opposite site) we checked our meter- checked the rest of the wall- there are no sign of leaking. We followed the direction on how to fix the blistering and the weather was hot and humid on all the times: 1st time: sand, clean, use primer (left over), and paint (left over)- we used the bathroom on the same day-the paint were blistering again and this time spread to a different areas. 2nd time: sand, clean, primer- we let it dry for 1 day and we painted the next day- a week later - they blistering (spreading) again. 3rd time: we got a different primer-KILL Z- repeated the step on #2- The areas we fixed were OK_ but now some blistering are shown at different areas. We are running out of ideas- really trying not to REDONE the whole wall since the photo 3 - the blistering spread to a different section of wall. If we have to REDONE, can someone give us what products we have to use and maybe trying to find the culprit? I assume it could be just too humid, and my husband has not opened the sky lights but the fan has been running at extended timer after using the shower.