Wood Trim

Wood trim adds character and finish to your home, both inside and out. Understanding how wood behaves and providing simple maintenance keeps trim looking great for years.

Understanding Wood Behavior

Wood is a natural material that responds to its environment. This is normal and expected.

Interior Trim Shrinkage

Shrinkage occurs during the first two years or longer, depending on temperature and humidity.

Key factors:

• All lumber is more vulnerable to shrinkage during heating season
• Maintaining moderate, stable temperature helps minimize effects
• Wood shrinks less lengthwise than across the grain

What you may see:

• Separation at joints of trim pieces
• Trim pulling away from wall
• Gaps at mitered corners
• Nail pops

Exterior Trim Behavior

Exterior trim is exposed to weather and shows more movement than interior trim.

Normal occurrences:

• Cracks (especially in cedar)
• Twisting
• Shrinking
• Raised grain developing over time

These are functions of natural wood's expansion and contraction with weather and are not defects.

Routine Maintenance

Task	Frequency	Time Required
Visual inspection	Seasonally	15 minutes
Touch up interior caulk/paint	As needed	Varies
Check exterior trim condition	Annually	30 minutes
Repaint/restain exterior	Every 3 to 5 years	Varies

Interior Trim Maintenance

Fixing Gaps and Separation

In most cases, caulk and paint are all that's needed to conceal minor evidence of shrinkage.

For gaps at joints:

1. Apply appropriate caulk (paintable caulk for painted trim)
2. Smooth with wet finger or caulking tool
3. Allow to dry completely
4. Touch up with matching paint

For trim pulling away from wall:

1. Drive in a nail close to, but not exactly in, the existing nail hole
2. Set the nail slightly below surface
3. Fill the old nail hole and new nail hole with wood putty
4. Allow to dry
5. Touch up with matching paint

When to Act

• Heating season: Gaps appear or worsen as humidity drops
• Humid season: Gaps may close naturally
• Best time to repair: After the second heating season when most shrinkage has occurred

Exterior Trim Maintenance

It is the homeowner's responsibility to maintain exterior trim areas.

Regular Care

Inspection

Check regularly for:

• Cracking or splitting
• Paint peeling or flaking
• Caulk failure at joints
• Signs of rot (soft spots, discoloration)
• Raised grain

Caulking

Re-caulk gaps as needed, especially:

• Where trim meets siding
• At corner joints
• Around windows and doors
• At any visible gaps

Use exterior-grade, paintable caulk.

Painting/Staining

• Repaint or re-stain as needed to protect wood
• Sun-facing sides need more frequent attention
• Address rot promptly before it spreads
• Proper prep (scraping, sanding, priming) is essential

Wood Rot

Since exterior wood is exposed to the elements, even when protected, it will eventually rot. This includes decking, railings, and trim.

To slow rot:

• Keep paint/stain in good condition
• Maintain caulking
• Address water intrusion sources
• Allow wood to dry (don't trap moisture)

If rot is found:

• Remove and replace rotted section
• Or use wood hardener and filler for minor damage
• Address cause of moisture

Troubleshooting

Gaps at Mitered Corners

1. Wait - Gaps may close seasonally
2. Caulk - Fill with paintable caulk
3. Touch up - Paint to match
4. Accept - Some movement is permanent and normal

Nail Pops

1. Drive nail back - Or set slightly below surface
2. Add new nail - Nearby if needed for holding power
3. Fill - Wood putty over nail heads
4. Paint - Touch up to match

Trim Pulling Away from Wall

1. Re-nail - Drive nail near (not in) existing hole
2. Fill holes - Both old and new
3. Paint - Touch up to match

Raised Grain (Exterior)

Raised grain is normal on exterior wood exposed to weather.

Options:

• Sand smooth before repainting
• Use grain filler
• Accept as natural weathering characteristic

Exterior Paint Peeling

1. Check for moisture - May indicate water intrusion
2. Scrape loose paint - Down to solid surface
3. Sand smooth - Feather edges
4. Prime bare wood - Essential for adhesion
5. Repaint - Quality exterior paint

What to Avoid

warning

• Don't ignore gaps - Especially exterior (allows water entry)
• Don't skip priming - Essential for exterior paint adhesion
• Don't trap moisture - Allow wood to breathe
• Don't delay rot repair - Spreads quickly
• Don't expect perfection - Wood movement is natural
• Don't fill gaps during humid season - They'll reappear when dry

Material Characteristics

Understanding that these are normal helps set expectations:

Characteristic	Normal?	Notes
Gaps at joints	Yes	Most noticeable in heating season
Nail pops	Yes	From shrinkage
Raised grain (exterior)	Yes	Weather effect on natural wood
Cracks in cedar	Yes	More prone than other woods
Color variation	Yes	Natural wood characteristic
Knots showing	Yes	Natural feature

Related Topics

• Paint and Stain
• Caulking
• Expansion and Contraction
• Siding and Stucco

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Warranty Coverage: See Wood Trim Standards for coverage details. Construction damage must be noted on orientation form. Shrinkage and normal wood behavior are excluded.