DCT04 Elizabethan Shield PVC 2' x 2' Ceiling Tiles - Lay-in or Glue-up Installation (Covers 40 sq.ft, Pack of 10) - Old Black White Design for Home, Office & Restaurant Decoration

I used the matte white tiles and glued them over a popcorn ceiling. These tiles are very strong and flexible and can be cut with scissors. They are overlapping tiles so I used a bead of glue under the overlapping portion and glued each tile together as I installed them in a seamless fashion. Beware of YouTube videos that claim easy installation over popcorn ceilings with water based tile adhesives. It might work if the popcorn has a coating over it, or is sealed with a coat of paint, but if the popcorn ceiling is over twenty years old, the chances are that it's bare and crumbling like chalk, and water based glue will not stick. It might stick at first but will come loose later. You risk having the entire ceiling of tiles coming down afterwards if they are overlapping and glued together. At first I had problems with the water based glue coming loose from the popcorn as I warned above. Because the tiles are overlapping and glued together, whole sections came off the ceiling together at one time. It was a near disaster. I concluded that it was the water based glue that was actually softening the popcorn underneath after absorbing the moisture as the glue dried and weakening the adhesion. Not one to give up, I went to a solvent based synthetic rubber glue instead. I used Lexel Sealant in the calk gun tube. I applied eight gulf ball globs of Lexel to each tile. Four around the flat in the center of the tile, and one to the flat on each corner. I discovered that after applying the glue to the tile you must let it dry for 15 minutes before sticking the tile to the popcorn ceiling. This allows the Lexel to get tacky and stick to the popcorn texture without problems. If you don't wait a full 15 minutes before installation the Lexel is too wet and will not adhere properly. I laid each tile bottom side up, one tile at a time, on a flat surface and applied the Lexel as previously described. After waiting 15 minutes, I applied a bead of water based adhesive to the overlapping portions, and installed the tile over the popcorn by pressing the adhesive applied center and corners to the ceiling. The overlapping portion of the tile with the water based adhesive can be secured by running your finger along the seam and wiping the excess that squeezes out with a damp rag. A word of caution while using Lexel, is to open a window nearby because the fumes are strong for the first hour or so after installation. After drying for 24 hours the tiles are firmly stuck to the popcorn and will not come off. Lexel claims that it's adhesive will stick to anything. I'm here to tell you that it will stick to a chalky crumbling popcorn ceiling so well that even after strong tugging on an installed tile it will not beak it loose no matter what.