The plaster keys holding it to the underlying lath can also crack and break over time causing the plaster to partially separate from the wall.
How to repair plaster ceiling cracks.
By using modern materials and a traditional technique it is possible to repair plaster ceilings that are cracking and delaminating.
If the plaster ceiling feels firmly attached to the lath then you can do the same repair as for the small cracks above.
Score the crack with a utility knife to remove any loose plaster or other material that may be inside the crack.
In this video this old house general contractor tom silva explains how to repair a plaster ceiling.
How to fix plaster ceilings.
House settling and temperature or moisture fluctuations in an attic which result in the expansion or contraction of framing members.
Besides the normal wear and tear of living plaster and lath ceilings are at the mercy of gravity and they can take only so many water leaks and structural movements before they pull away from the framing.
For larger cracks you may need two coats of spackle because of its tendency to shrink as it dries in large gaps so double check before priming and painting.
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No matter what the cause you can repair the plaster cracks by using drywall tape and joint compound.
What old house owner doesn t have a cracking or sagging plaster ceiling in need of repair somewhere.
Typically plaster ceiling cracks have two causes.
Screw plaster washers to ceiling along and around cracked area.
Ask this old house general contractor tom silva helps a homeowner repair a cracked plaster ceiling in an older home.
The plaster must be firmly anchored to the lath behind it.
Use trowel to spread joint compound onto ceiling covering the repaired area.
Use mesh tape to cover the crack.
Here is a step by step guide to how to fix plaster ceilings in your old house.
If when you push on the wall it flexes as though it has broken away from its support base call a plaster specialist the repair will involve removing the loose plaster and replacing it.