All the trim in our 5yr old house is separating from the wall and the joints (miter, butt) are cracked. So I decided to fix it by re-caulking with DAP Alex Plus caulk and repainting.

One month after finishing the job the joints are already cracked again?????

Some notes:

-Temperatures during this month ranged from +12C to -22C

-The crack gap is small (1mm or less) meaning very little caulk gets in the crack

-The trim seems well secured as I cannot push the crack closed with force. It seems more like expansion and contraction from temperature and humidity is the source of the problem

Possible solutions

-Use pure silicone (paintable) instead of acrylic or siliconized acrylic

Any other thoughts or suggestions on how to get a lasting seal of these joints and cracks????