One of my “favorite” parts of working on a home is the discovery. My nee home has a laundry room that appears to have excessive water damage. Before I out up new drywall I think I need to remove the old ceiling.

I cut a whole and took a picture. The ceiling seems to be approx 1/2 inch thick cement like and crumbly.

When I took the picture there is a granular green surface.

Any ideas of what it is?