Delaminating cracks these cracks are a sign of plaster pulling away from the lath behind it.
Roof leaked and niw my ceiling plaster is cracked.
Lay drywall jointing compound along the crack on top of the tape.
Typically plaster ceiling cracks have two causes.
House settling and temperature or moisture fluctuations in an attic which result in the expansion or contraction of framing members.
If your ceilings are plastered cracks are often attributable to weathering of the plaster.
Cracks in drywall can be caused by truss uplift or vibrations from an appliance such as a ceiling fan.
Large cracks and a bowed ceiling.
Ceiling cracks in plaster ceilings.
Small cracks can be repaired by applying plaster.
When plaster begins to pull away from the lath there is a chance it may fall away from the wall or ceiling and come crashing down.
If the crack is between drywall sheets along ceiling joists then use drywall screws to hold the two sheets of plasterboard immobile and approximately level with each other.
These show up on both ceilings and walls but can be the most dangerous on ceilings.
If you live in a home with plaster ceilings and you begin to see cracks they may be caused by moisture and or movement.
The jointing compound will cover the tape and be reinforced by the tape.
In addition water damage from roof or plumbing leaks can discolor plaster and cause peeling or efflorescence the leaching of salts and minerals to the surface.