5 Signs of Wood Rot You Should Catch Before You Paint

Paint is not a repair. It's easy to assume a fresh coat will cover up minor damage, but painting over wood rot just seals moisture in and hides a problem that gets worse underneath. Here's what to check before any paint goes on.

• 1. Soft or spongy trim. Press on window sills, door frames, and fascia boards. If it gives under light pressure, that's active rot, not just old wood.
• 2. Peeling or bubbling paint in one specific spot. Paint failing in the same localized area repeatedly (rather than across the whole surface) usually means moisture is getting in from underneath.
• 3. Discoloration or dark staining. Water intrusion often leaves a stain before the wood visibly softens — catching it here is cheaper than waiting for full deterioration.
• 4. A hollow sound when tapped. Wood that's rotted from the inside out can look fine on the surface but sound hollow when you knock on it — a simple test most homeowners skip.
• 5. Visible gaps where trim meets siding or the foundation. Gaps let water in continuously, which is often where rot starts in the first place, especially around window and door frames.

Why this matters before painting specifically

If any of these are present and get painted over anyway, the rot continues underneath the new paint — which means the paint job fails early and the repair costs more once it's finally addressed. Catching it first means the paint job actually lasts.