How to install plaster ceiling medallions

In the old days, ceiling medallions were permanently plastered in place by the plasterers. Back then there was usually not an electrical box present. Ideally, you would like access to the box in case there is ever anything wrong . If it is permanently attached you might end up destroying the medallion in order to get to the box since the medallion goes over and partially covers the box . What we usually suggest to avoid this is to use trim head dry wall screws. They are like a finish nail with a reduced size head. You need to locate the wood joists or some solidly attached lath behind the plaster for the screws to securely grab onto. You also need to pre-drill pilot holes in the medallion in the locations of the wood and screw them in while holding the medallion in place. 

Once this is done you can take a picture or make note of the screw locations on the medallion before they are covered over by spackle or some other filler so you'll be able to find the screws later. Also, protect the head of the screw from being filled in by the spackle. A punched out paper circle from a hole punch works pretty well or some bit of tape. This way, should you ever need to remove the medallion to work on or change the electrical box you can. All you will have to do is relocate the screw heads from your photo or notes and dig out the spackle and paper and back out the screws to remove the medallion. 

Many of our customers have either the electrician or painter or sometimes a carpenter put up the medallion. In any case make sure your electrical box is in good condition and securely attached to the ceiling. Make sure there is enough wire to come down through the medallion and still have enough left to make a connection inside the canopy of the light you are hanging on the face of the medallion. Typically that would mean having about 6 to 8 inches of wire exposed after the medallion is in place. Please note that the canopy of the light, once in place, will also help hold the medallion in place. 

It is also recommended that you put a primer coat of paint on the back side of the medallion to prevent water or moisture from soaking in from the back side. If there ever is a leak, the plaster will act as a sponge unless sealed or primed. By the time you notice the leak it will be too late to save the medallion. Some of our customers do plaster the medallions in place and hope for the best. In that case ask your plasterer. Painting the back of the medallion might interfere with his methods of attaching it. You can also glue the medallion in place, if necessary, with construction adhesive. You would have to seal or paint the back side very thoroughly as construction adhesives will not stick to raw plaster (it is too powdery a surface). This is also a permanent method that would be very tough to remove without damage once done.