Door casing

Hello all,

Need a little help. In our house we have drywall and then plaster on top of the drywall. We installed new Prehung doors, but the casing isn’t working. The walls extend out past the jambs on both sides. My thought process was to cut back the plaster wall so the casing would fit in and not rock back and forth. This a good way to go about it or there more options.

 

Here are instructions for posting pictures. Seeing what you have will help a lot.

If your walls are not straight and/or plumb you really need to stand back and see what will be best. If the hump in your wall is sorta minor you can shim the door frame to be vertical then putty or caulk the gap behind the molding to conceal it. If your wall is really bowed you might not want to hog out all of the hump as the reveal on the side of the molding will show the wall's bow. You may want to do a bit of both methods to better conceal the hump in the wall.

 

If it's more than 1/8" you generally need to add a strip of wood onto the jamb that will build it out flush with the wall.

Once you have done that you are ready to put casing on. The standard method is to step any extension jamb back about 3/16" rather than try to flush it up... then the casing steps back another 3/16". That step is called "reveal".

If it's only 1/8" then yes, you can take a grinder and bevel the plaster back so that the casing can tip back toward the jamb. The problem this creates is that it turns your casing miters into compound cuts. (No longer a perfect 45 degree miter with 0 degree bevel.)