Carpentry and Woodworking - craftsman trim on drywalled window

First of all, let me say I have super basic knowledge of carpentry,so I understand basic carpenter speak.

Any reason why I can't build a craftsman-style trim around a window without tearing out the drywalled jambs (bottom, top and sides are currently drywall)? Can't i build the craftsman-style (from douglas fir which will be stained) jamb with stool and casing right on top of that drywall?

thanks.

You have 2 considerations. Whether the jamb will fit and not look stupid... and whether the casing will lay flat with no gaps behind the trim around the perimeter.

If the thickness of the 1/2" drywall returns don't build the 3/4" jamb out past the window, you could probably leave them. I'd recommend you tear them off so that you can shim the jamb to the opening.

If there is currently only 1/2" (for example) from the drywall to the edge of the window, then you ought to remove the drywall that returns to the window.

If there is 1" from the drywall to the edge of the window, that is perfect... 3/4" for the jamb and about 3/16" for a reveal, or step that you should have where the jamb meets the window.

Additionally, the corner bead around the opening will prevent the trim from laying perfectly flat on the wall. If you lay a framing square diagonally across the corner, I think you will see what I mean. This will create a gap behind your face trim. If you don't mind shimming the back side and caulking it, then it's not a problem. But if you want it to lay flat with no gap behind the trim (stain grade) then I would recommend you should remove the corner bead and belt sand the joint compound around the perimeter of the opening in an area that will be covered by your trim, so that it's not built out farther than the rest of the wall is.

Tearing off the drywall and corner bead is not that big of a deal. Put dropcloths down and have a shopvac handy to clean up.

No reason I know of, go for it.

Go for it. I have done the same thing several times with painted material when the owner did not want to pay for tearing the rock out and installing wood jambs. You may be able to do a faux finish on the "jambs" to make it really look good. I never liked drywall jambs.

Bill

I just realized that after tearing off the bead and drywall sides, top and bottom - I would be covering up all of that evidence with the new jams and trim (though would have to add a piece of trim underneath the apron to cover up that "evidence"). See, the walls have a fresh coat of paint and I was hoping to not have to mess all that up. I laid a piece of the 3/4" material against the drywall, and it'd leave just a pinch of room to be able to get my fingernails behind the window "bar" that one uses to slide the window open. So, it looks like the best approach would be to tear it up.
thanks for the recommendations