Can I install drywall on the ceiling, without removing crown molding?

Question

I'm in the process of replacing a failing plaster ceiling in my finished basement with drywall. I originally had intended only to scrape down the popcorn finish and have it skim coated, so I did not initially try and remove the molding. Once I got down to the original plaster and saw the extent of the repairs that would be needed, I decided it was going to be more cost effective to just replace it. I had already draped the room in plastic from the molding down, and it was looking tough to get a pry bar in there, so I left it figuring I could remove the majority of the ceiling and then remove it when I had access from above.

Well now I have that access, but it still looks to be a challenge:

• It is 85 years old, and while it's in great aesthetic condition, in reality, the wood is dried and quite fragile. If I try to remove it, I'm likely to end up damaging some pieces.
• The bottom portion of the molding is flush with the plaster walls and it is nailed directly into the lath, maybe even glued? When I tried to gently pry it off, the whole plaster surface moved along with the molding.

So given this, I'm wondering if I can get away with installing the drywall without removing the molding? There is 3/4" of space between the joists and the molding, so 1/2" drywall would fit fine, and due to slight unevenness in the joists I need to shim down about 1/4" anyway.

Is this a terrible idea, or does anybody have tricks for gently removing old crown molding from plaster? It would be easier to hang the drywall with the molding off, as I could strap the ceiling and shim the strapping. As is, if I did this I guess I would have to shim the joists themselves with plywood strips.

EDIT: The crown molding is stained oak, which means pretty much any nick shows and damage of any substantial size is tough to re-stain to the right color. I am pretty attached to it, so I'd prefer to keep it intact.

Answer 1

Go ahead and place the drywall over the top edge of the crown moulding. Sounds like the wall was already re-plastered with it in place. If you tried to remove it, you may end up re-doing the walls as well. Even forgetting that, it's almost impossible to remove moulding without sustaining some loss. Without replacement material available, removal with intents of preservation is extremely risky, especially with stain grade material. You don't want to go there.

If your joists were flat, you'd still only need to shim down the first 4 feet or so along the walls, no one will see the resulting slight slope. Keep this in mind when planning your shims. It doesn't have to be perfectly flat, unless that gives you pleasure. You also don't need to shim to completely fill the gap. An 1/8" gap makes a clean shadow line that is not detrimental (assuming it is perfectly uniform) at all. It also makes finishing easier. The taped joints of drywall are normally not perfectly flat, despite the tapered edges. There is a slight bulge which is usually invisible. But against straight moulding, depending on the profile, this bulge may be visible. You might consider grinding down the edge tapers at the board corners against the wall so the joint tape can be completely buried and the yet the joint against the moulding can still be perfectly flat.

Answer 2

Next time check out "Big Wally's Plaster Magic", or similar glue based repairs. Basically you drill a few holes, inject glue, then clamp the failing plaster back up. You can save a ceiling (or in your case, save the wall where you messed with the crown molding). Removing the crown molding sounds too risky.