Seams

[Jdeal1]

What makes these seams appear around my house? It’s only 6 years old.

there are some upstairs downstairs all around.

 

[Snoonyb]

Expansion and contraction and one of the cures is more screws and drywall repair.

 

[Jeff Handy]

Extreme changes in humidity during the year, which makes the joists move.

Too much weight on the floor above.

Poor framing technique, no blocking or cross bracing.

Poor drywall taping technique.

Leaking water from above, rain or toilet or bathtub.

Not enough screws in the drywall sheets.

Foundation settling slightly.

Drywall was glued with construction adhesive to the joists, and was not installed quick enough, glue skimmed over and never grabbed properly.

 

[DFBonnett]

What JH said ^, but my bet would be on a bad tape job.