Good Morning Cathy,

Great question!

Prior to installation, it is recommended that the entire ceiling be
smooth and flat. Apply a drywall primer
or paint primer. With textured ceilings,
or popcorn ceilings, you can scrape/sand down your ceiling or nail up a layer
of plywood to attain that smooth surface. Being that our panels are textured they
must have an extremely smooth, flat surface or they will pull away from the
ceiling. The Pl Premium construction
adhesive, that we recommend, will soak into the popcorn material of the ceiling
rather than cure solid with the panel.
This will cause the panels to fall down

Thanks again!

Britni-DIY DECOR