If they are bigger and sections of plaster are falling you will probably have to remove the plaster and replace it with a drywall section.
What causes cracks in drywall ceiling.
If you live in a home with plaster ceilings and you begin to see cracks they may be caused by moisture and or movement.
A wall is constructed with vertical studs that extend from floor to ceiling.
Typically plaster ceiling cracks have two causes.
Cracks in a drywall ceiling are caused by wood movement in the framing due to shrinkage of improperly dried lumber or seasonal changes in temperature and humidity.
Damaged ceiling joist or trusses.
Drywall cracks in ceilings or walls.
The best way to repair a crack in drywall is to re tape the joint.
House settling and temperature or moisture fluctuations in an attic which result in the expansion or contraction of framing members.
These structural members sit on top of the wall plates and are often connected to the plates with nails.
Causes of cracks in walls.
Cracks around door frames windows and the ceiling can also indicate your foundation is settling.
This is a sign of structural damage usually related to a weak wall.
If you find cracks in these areas beery recommends another test.
This article describes the common causes of all types of cracks that appear in drywall or gypsum board or plasterboard walls ceilings in building interiors.
When the wood rafters expand and contract naturally with changing temperature and humidity it pulls the ceiling joists away from the wall plates.
Too much mud too little mud missing drywall tape and drywall secured with internal stresses are some causes removal of pop corn textured or cottage cheese looking ceiling material may leave a drywall taping job that tends to crack at the drywall joint.
Small cracks can be repaired by applying plaster.
Cracks that cause concern are those which run across the length of a ceiling and then continue down a wall along the same line.
Occasionally a ceiling joist or a truss becomes damaged or cracked this weakens the framing member and the ceiling will bow or sag in.
See if the door or window.
Illustrations show where cracks are most likely to appear explain why and suggest both repair approaches to drywall cracks and how to prevent cracking in plasterboard or gypsum board.
When the ceiling joist or trusses are undersized for the drywall ceiling weight that they re carrying.
One of the most common causes of cracks in drywall ceilings is related to the roof trusses.