House settling and temperature or moisture fluctuations in an attic which result in the expansion or contraction of framing members.
Repairing plaster ceiling cracks.
What old house owner doesn t have a cracking or sagging plaster ceiling in need of repair somewhere.
Plaster applied to wood lath is held in place by the keys that form when it squishes through the lath.
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.
To repair a crack in a ceiling.
An overview photo by david carmack.
No matter what the cause you can repair the plaster cracks by using drywall tape and joint compound.
Typically plaster ceiling cracks have two causes.
Be sure to drive screws into wood lath above.
He asks us in an e mail.
Use trowel to spread joint compound onto ceiling covering the repaired area.
Expert advice and detailed instructions on repairing the most common plaster wall and ceiling problems including cracks holes and sagging.
Step 1 remove any loose plaster that s embedded in the crack.
Screw plaster washers to ceiling along and around cracked area.
For more about how plaster walls are built see plaster wall construction over time these.
If the plaster ceiling feels firmly attached to the lath then you can do the same repair as for the small cracks above.
Otherwise the cracks come back no matter how many times you patch over them.
Plaster repair is much.
If it s a small hairline crack you won t have to worry about this but larger deeper cracks will have debris in them.
To repair small cracks in plaster you ll need patching compound medium and fine grit sandpaper a sanding block a putty knife a masonry chisel a paintbrush a rag and a screwdriver.
A ceiling crack is not an uncommon sight in older homes.
The key to any fix is to reunite the plaster with the strips of wood lath underneath.
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.
Here tom silva shows how to repair plaster walls to make them look as good as new.
Repairing small cracks in plaster is easy compared to plastering a whole room.