If you've lived in Charlotte for any length of time, you know our weather doesn't do anything halfway. Summers are sticky and humid. Winters bring dry heat from furnaces running overtime. And your hardwood floors feel every bit of it.
I've been working on floors in the Charlotte area for nearly two decades, and humidity-related problems are easily the most common issues I see. The good news? Most of these problems are preventable with some basic awareness and a few simple tools.
Why Charlotte's Climate Is Tough on Hardwood
Wood is a natural material that absorbs and releases moisture constantly. When the air is humid, wood absorbs moisture and expands. When the air is dry, wood releases moisture and contracts.
In a stable climate, this isn't a big deal. But Charlotte has what's called a humid subtropical climate - we swing from 80%+ humidity in summer to indoor humidity levels below 30% in winter when the heat is cranking.
That constant expansion and contraction is what causes problems.
The ideal indoor humidity range for hardwood floors is 35-55%. Stay in that range year-round, and your floors will thank you.
What Happens When Humidity Is Too High
During Charlotte summers - roughly May through September - outdoor humidity regularly exceeds 70%. That moisture seeps into your home, and your floors start absorbing it.
Here's what you might notice:
- Cupping: The edges of boards curl upward while the center stays flat, creating a wavy appearance. This happens because the bottom of the board absorbs more moisture than the top.
- Crowning: The opposite of cupping - the center of boards rises higher than the edges. This often happens after cupping has occurred and the top of the board finally absorbs moisture too.
- Sticky finish: If your floors feel tacky or the finish seems soft, excess humidity may be preventing proper curing or breaking down the finish.
- Doors sticking: Hardwood doors swelling in their frames is often the first sign that indoor humidity is too high.
If you catch cupping early, it often reverses on its own once humidity levels normalize. But if you leave it too long, the boards can permanently deform.
What Happens When Humidity Is Too Low
Once October hits and we start running the heat, the situation flips. Forced air heat is incredibly drying - I've measured homes in Charlotte where winter indoor humidity dropped below 20%.
Low humidity causes:
- Gaps between boards: As wood contracts, you'll see visible gaps appear, especially between wider planks. Some seasonal gapping is normal, but excessive gaps collect dirt and are a sign your humidity is too low.
- Cracks and splits: Severe drying can actually crack boards lengthwise. Once a board splits, it's damaged permanently.
- Finish checking: The finish can develop tiny cracks (called checking) when the wood beneath it shrinks faster than the finish can flex.
- Squeaky floors: Gaps allow boards to move more, creating squeaks and creaks underfoot.
How to Monitor Indoor Humidity
You can't manage what you don't measure. A simple hygrometer - the tool that measures relative humidity - costs $15-30 and is worth every penny.
I recommend:
- Get a digital hygrometer with a display you can read at a glance. Place it in a central location away from windows and vents.
- Check it weekly and note the patterns. You'll quickly learn how your home responds to weather changes.
- Set alerts if your hygrometer has that feature. Many smart models can notify your phone when humidity goes outside your target range.
Aim to keep your home between 35-55% year-round. If you're consistently outside that range, it's time to take action.
Solutions for High Humidity (Summer)
When Charlotte's humidity spikes, here's how to protect your floors:
- Run your AC consistently. Air conditioning doesn't just cool - it dehumidifies. Setting your AC to run more steadily (rather than big temperature swings) helps maintain consistent humidity.
- Use a standalone dehumidifier in problem areas like basements, crawl spaces, or rooms that don't get good air circulation.
- Check your crawl space. Many Charlotte homes have crawl spaces that can harbor moisture. A vapor barrier and proper ventilation down there makes a huge difference upstairs.
- Ventilate bathrooms and kitchens properly. Run exhaust fans during and after showers and cooking.
Solutions for Low Humidity (Winter)
When the heat kicks on and humidity plummets:
- Use a whole-house humidifier if your HVAC system supports it. These are the most effective solution for maintaining consistent humidity throughout your home.
- Portable humidifiers work well for individual rooms or smaller homes. Just stay on top of cleaning them to avoid mold issues.
- Keep temperatures moderate. The higher you crank the heat, the drier the air becomes. Even dropping from 72 to 70 degrees can help.
- Add some houseplants. They release moisture through transpiration. It's a small help, but every bit counts.
Warning Signs You've Waited Too Long
Sometimes humidity damage sneaks up on you. Call a professional if you notice:
- Cupping or gapping that doesn't resolve after humidity normalizes for several weeks
- Boards that have cracked or split
- Finish that's peeling or flaking
- Significant color changes in the wood (often indicates moisture penetration)
- Mold or mildew smell near your floors
Catching problems early means they're usually fixable. Waiting too long can mean refinishing or even replacing boards.
The Bottom Line
Managing indoor humidity isn't complicated, but it does require attention - especially in Charlotte's climate. A $20 hygrometer and some awareness of seasonal changes can save you thousands in floor repairs.
If you're seeing signs of humidity damage already, or you're just not sure what you're looking at, give us a call. We're happy to take a look and tell you honestly whether you've got a problem or just normal seasonal movement. No pressure, no sales pitch - just straight answers about your floors.