My house is about 109 years old, excellent condition, other than cracking in the plaster ceilings. I've had one 3x3 section even fall out in my dining room. I want to replace the ceiling in the dining room with dry wall and put up imitation metal tiles. This will probably cost about 1k-2k to finish. Should I just patch the hole in the ceiling with plaster, or tear it all down? I also have some soon to be serious cracks in my living room ceiling starting now too.
CAUTION ALERT ! Dealing with a failing plaster and lathe ceiling can be very tricky. Before you make the decision to tear it down, which as Chris mentioned, a messy job, or simply put drywall over the existing plaster, you need to carefully evaluate the soundness of the lathing to the strapping or joists. What I mean by that is, are the lathes still firmly attached to the joists and the problem is the plaster "keys" failing from around the lathes, or are the lathes themselves falling away from the joists?
With that said, covering the old failing plaster with drywall is fine. If the lathes are solid to the joists, then putting drywall directly over the old and using screws long enough to reach the strapping or joists will work fine. However, if the lathing itself is failing, then you must install strapping 16 inches on center, perpendicular to the joists, securely screwed to or ring nailed to the joists. The purpose of strapping is twofold. First reason is to support the failing ceiling securely to the joists. The second reason is that if you just screw drywall to the failing plaster and lathe, the weight of the ceiling will be against the drywall and could pull the screws through the drywall board allowing it to sag or joints to crack now or in the future.
I must say that even though tearing down the old ceilings is a big job, it certainly gives you a clean start and an open view to correct any old wiring problems, add new lighting circuits, install new flush mounted electrical boxes, and install new level strapping etc.
You can just plasterboard (drywall) over the ceiling but there are a number of things you have to be aware of:
- Make sure that you use longer screws/nails go through the existing ceiling and far enough into the joists. In an old house the previous occupiers has boarded over a bad ceiling but used the normal sized fixings. By the time we came to sort it out there was quite a bow in the ceiling. This was caused by them using normal sized nails and the extra weight caused the old ceiling to come away even more from the joists.
- Make sure that the rest of the existing ceiling is sound. If (as Shirlock points out) that is coming down in more places you will get the problems I outline above
- You will have to take more care to find the joists as you can't see them.
- If the hole is large then you will have to put something there to make sure that the new board doesn't form a "dip".
- Bringing an old ceiling down is a very messy job.