Key takeaways
- Wood swells and shrinks with humidity, mostly across the grain.
- Seasonal gaps and sticking doors are usually normal movement, not defects.
- Good carpentry allows for movement with the right fasteners, gaps and finishes.
Why wood moves
Wood is made of cells that take on and release moisture from the air. As humidity rises it swells, and as it falls it shrinks, mostly across the width of the board rather than along its length.
Middle Tennessee has humid summers and drier, heated winters, so houses see a real seasonal swing.
What you notice
Doors may stick in July and rattle in January. Hardwood floors may show small gaps in winter that close in summer. Trim joints can open slightly at corners, and caulk helps hide the movement.
Large movements can signal a moisture problem, such as a damp crawl space or a leak.
How good carpentry handles it
We use stable materials, acclimate lumber and flooring, leave expansion gaps and use fasteners and joints that allow movement. Sealing all sides of exterior wood, including end grain, slows moisture changes.
Keeping indoor humidity moderate with proper ventilation, a dehumidifier or a humidifier in dry winter air helps wood stay calm.
Related services
Quick answers
What indoor humidity is best for wood?
Many wood suppliers suggest roughly 30 to 50 percent relative humidity indoors, which is also comfortable for people.
Why did gaps appear in my new floor?
Small seasonal gaps are normal as boards shrink in dry winter air. Large or permanent gaps can signal a moisture or installation problem that should be checked.
Ready to talk it through? Get a free estimate or call 615-431-3789.