Why You Should Prime a Wall Patch Before Painting

When repairing a wall, many people are tempted to paint directly over a dried patch. While it may look fine at first, this shortcut often leads to a noticeable problem known as flashing. Flashing occurs when patched areas absorb paint differently than the surrounding wall, leaving behind dull or foggy spots once the paint dries.

Most patching compounds are more porous than finished drywall. When paint is applied directly over them, the patch soaks in more paint than the rest of the surface. This uneven absorption changes the sheen and texture of the final coat, making the repair stand out instead of blend in.

Priming the patch solves this problem. A sealing-type primer creates a uniform surface by blocking excess absorption and ensuring the paint dries evenly across the wall. As an alternative, some self-priming patching compounds are designed to eliminate the need for a separate primer step, but traditional patches almost always require priming.

Taking the time to prime patched areas before painting leads to a smoother, more professional finish—and prevents repaired spots from calling attention to themselves after the job is done.