Ceiling Crack

Home is 10 years old. Ceiling cracks began to appear last year. Have become worse this year.

Possible causes?

Too many possible factors here. Is there a floor above? Have there been high winds recently?

Are you storing heavy boxes in the attic? (assuming there is no 2nd floor)
Do you have any cracks elsewhere in the house?
Do the doors and windows operate properly or are they sticky (rub on their frames)?

The home is a bungalow. There is nothing stored in the attic. Windows and doors seem to open fine. Cracks are in the southern 1/3rd of the house. No other cracks elsewhere. Cracks are only on the ceiling, none around doors or windows.

I would bet that at one time it was a scissor truss open cathedral design and they infilled the section with bulkheads. Thing is it will not work as the design of a scissor truss can’t accommodate the change.

No unfortunately that is not the case either. The trusses were engineered trusses with the cathedral built into the design.

Really at a loss on this…

Joe you will need to explain the truss design as to which one it is. Scissor trusses are engineered for Cathedral designs.

Where are you located Joe?

Thermal expansion/contraction…truss uplift or trusses incorrectly fastened to non-bearing partitions…

Temperature extremes in last season vs others? I only ask as you indicate cracks isolated to southern 1/3 of home… winter=cold/wet lumber and expansion… Summer creates shrinkage via warm/dry wood, either of which can affect trusses as the bottom chord remains insulated and other components are exposed to temp differentials.

Framing inspection in affected areas, move insulation away from truss/wall areas (esp interior) and see if any sense can be made to problems, such as framing defects etc.

Hire a pro or be careful up there!

Are your gutters and down spouts working effectively? Is there negative drainage around the home?