I needed the ceiling to be light strong and reliable. My room was going to be 4' x 7' (plus a few inches) so I got a 4x8 sheet of half-inch foam board, cut off a foot and glued it onto a 4' x 7' wooden frame made of 1.5' x 0.75 studs. I used only one cross bar for the frame. I bought two 4' lengths of quarter-inch "coarse threaded rod" metal stock and cut them to 1.5' lengths. I carefully drilled four quarter-inch holes in the frame as perpendicular as I could and glued the rods into the frame to act as guides for the spikes. I wrapped the metal rods in masking tape so that the threads would not rub on the frame for the spikes.
I then numbered the skulls and placed them on the foam board in the arrangement I wanted. I marked the placement of the eye sockets and drilled out 1.5" holes. I put a numbers by the holes so that I could match the skulls to the hole pairs later on.
Next, I made the frame that would hold the spikes. It was essentially three crossbars held in place by two connecting boards. I drilled a good size hole in each end of the connecting boards and reinforced the end with a metal bracket. These holes fit over the threaded rods. and acted as guides. I used wood screws to attach 12 wooden blocks on the underside of the spike frame (they were spaced about 1.5 feet apart.
Next, I attached six cut sheets of hardboard to the blocks. I then returned the spike frame to the ceiling and marked where the holes were. I bought a couple of packages of the Velcro sticky pads at the grocery store and placed the adhesive end over the marks. These pads will hold the spikes to the frame, but also allow them to be easily removed.
Now, it was time to glue the skulls inplace. I used one woodscrew through the back to hold it in place initially and some polyurethane expanding glue (the Elmers Ultra) and carefully aligned them with the holes. I put down some Great Stuff spay foam to add a little flair, covered the skulls with foil, then spray painted with a stone-texture spay paint (one of the Home Accents paints from Home Depot). I wiped the texture off the Great Stuff foam before the paint dried then repainted that part red.
