Aging, dried paint starts with hairline cracks. Eventually cracking to the surface.
CHECKING PROBABLE CAUSES
Poor surface prep. Applying paint too thin. Loss of elasticity, not expanding or contracting with humidity and temperature. As wood swells, stress breaks the bond between layers and checks form. Checking on unprotected wood is due to delamination.
Remove all loose paint with a scraper, wire brush or power washing for large areas. Feather sand edges. Level uneven areas with exterior spackle, sand and rinse with a garden hose to remove all dust particles.
PRIMERS & INTERIOR FINISHES
Priming is essential for better adhesion, sheen uniformity, mildew control and durability. Select a top quality interior paint in the color and sheen of your choice.