A year and a half ago I used Alex Plus Dap Paintable Caulking around all of my baseboards, mitre joints, door frames, etc. After caulking I left it as is and never painted except for the door frames. Now, the majority of the caulking has cracked, even in the door frames where I painted. What causes this?
The baseboards and door frames are pre-primed MDF which were painted prior to installation.
The low level DAP stuff is weak. Sherwin Williams makes a good caulk.
I agree. Causes of caulk failure are usually low grade caulk, caulking on an un preped surface, an un primed surface, or using the wrong king of caulk for the task at hand. I have my guys always use sherwin Williams siliconized acrylic 45yr and 55yr caulk for interior and exterior caulking. It adheres well and is flexible, so it will move with any settling and its siliconized, but its also paintable. I would remove the caulk and start over with a premium quality acrylic caulk.