How to Troubleshoot Swollen Door Trimming at Home

Quick answer (read this first)

• Identify the cause: moisture, humidity, or water damage.
• Dry the affected area thoroughly.
• Sand down minor swelling for a smooth finish.
• Consider repainting or sealing for prevention.

Safety first

• Wear safety glasses to protect eyes from dust.
• Use gloves to avoid splinters and protect hands.
• Ensure good ventilation when sanding or painting.
• Unplug any power tools before making adjustments.

Tools you may need

• Moisture meter (optional)
• Hair dryer or fan
• Utility knife
• Putty knife or scraper
• Fine-grit sandpaper (150-220 grit)
• Wood filler or caulk
• Paintbrush or roller
• Measuring tape
• Pencil

Step-by-step

Step 1

Identify the Cause & Damage: Thoroughly inspect the swollen trim for signs of moisture, water damage, or mold. Determine the extent and specific areas affected.

Step 2

Eliminate the Moisture Source: Immediately fix any leaks. For humidity, use a fan or dehumidifier to thoroughly dry the affected area over several hours or days.

Step 3

Ensure Complete Drying: Allow the wood to dry completely. For faster drying of small sections, use a hair dryer on a low setting, keeping it a few inches away.

Step 4

Gently Sand Swollen Areas: Once dry, use fine-grit sandpaper (150-220 grit) to carefully sand down the raised areas until they are flush and smooth with the surrounding trim.

Step 5

Fill & Smooth Imperfections: Apply wood filler or caulk to any remaining gaps, cracks, or minor depressions. Let it dry completely as per product instructions, then sand smooth.

Step 6

Clean & Prime: Thoroughly wipe down the trim to remove all dust and debris. Apply a primer if required, especially before painting, to ensure proper adhesion.

Step 7

Apply Finish Coat: Once primed (if needed), apply a fresh coat of paint or a protective sealant. This helps prevent future moisture damage and restores the trim’s appearance.

Common mistakes

• Not addressing the moisture source, leading to recurring swelling.
• Sanding too aggressively, which can damage the trim’s profile.
• Painting over wet or damp wood, causing peeling or bubbling.
• Using incorrect wood filler or caulk for the application.
• Ignoring minor swelling, which can worsen over time.

When to call a professional

• If swelling is severe and affects structural integrity of the door frame.
• When water damage is extensive and visible mold growth is present.
• If you suspect a hidden plumbing leak or roof leak causing the issue.
• If you are uncomfortable performing the repairs yourself.
• If the swelling persists after attempting DIY fixes.