My indoor ceiling in the house is plastered on reeds. Incredibly porous and hopeless to attach something heavy to, I think. In one room, I installed a new ceiling on battens that were attached with nail plugs. It worked, but the job itself was difficult and not all the nail plugs held very well, very time-consuming as well. In another room, I glued a new ceiling, the room was small so I could use smaller boards that weren't too heavy. That worked somewhat, but it took a lot of glue and I also had to secure them a bit with clips that I drilled directly into the concrete for support before the glue dried. Now I need to install a ceiling in the living room, but it's large and I thus want to use larger panels. I need tips on how to attach them to the porous concrete. Screws that grip the concrete? Glue that dries quickly and can handle the weight? Tips, ideas are welcome.
Not that it will be easier or less work, but wouldn't it be better to remove the old plaster and reeds so that you have clean concrete to work with?