The walls in my house are plaster and have several large sheetrock patches covering areas where windows and doors used to be located. The seam between the plaster and the sheetrock is cracked, which makes the patch appear obvious. What can I use to fill or cover the seams so that they won't crack?
Randy ~ Springfield, MO
Hi Randy, I don't necessarily think your cracking joint problem is due to a sheetrock patch meeting the existing plaster walls -- I think it's due to where these joints are located. When sheetrocking a room, it's common industry knowledge that it's best not to have a board joint at the top or bottom edge of a window or door. This is because the framing in a house moves and these areas are points where the movement can be enough to cause a crack in the joint compound over the seam. There is often added stress due to the window or door being opened and closed, but this shouldn't be a factor in your situation.
My suggestion is to use paper drywall tape with a good bonding agent when making your plaster repair. I have been told that wetting the plaster in the area where the tape will be applied can also be a good idea. The theory is that the plaster can wick moisture from the joint compound and cause the tape to not adhere properly. You just want it wet so any excess water should be removed prior to the tape going on. A blocking coat and a skim coat of drywall compound should also be applied.
I am not aware of any drywall compound that allows movement without cracking once it has dried. You may want to have a drywall contractor from around Springfield take a look at the problem to see if they can arrive at a simple solution, but my personal opinion is that you may continue to have some cracking with the sheetrock joints located in those areas.