Why Hardwood Floors Buckle: A Local Contractor's Guide for Mainline and Bucks County Homeowners

By the team at Cyclone Hardwood Floors, LLC

After 20+ years of working on hardwood floors across Montgomery and Bucks Counties, I've seen just about every flooring problem you can imagine. But one of the most frustrating issues homeowners call us about? Buckling hardwood floors.

Just last month, I was in a beautiful colonial in Bryn Mawr where the oak floors in the kitchen had buckled so badly you could actually see the boards lifting off the subfloor. The week before that, we got an emergency call from a homeowner in Newtown whose entire first floor looked like a wave pool after their water heater leaked. And don't even get me started on what happens to floors in Wayne and Radnor basements when sump pumps fail during our spring storms.

Here's the thing about buckling floors: they don't happen overnight, and they're almost always preventable if you know what to look for.

What Exactly Is Floor Buckling?

Let me explain this the way I explain it to customers: imagine your hardwood floor is made up of thousands of individual pieces of wood that need to breathe. When those boards absorb too much moisture too quickly, they swell. Since they're nailed or glued down and can't expand outward, they have nowhere to go but up. That's buckling.

It's different from cupping (where boards curl at the edges) or crowning (where the middle of boards rise up). Buckling is the most severe form of moisture damage—we're talking about boards actually detaching from the subfloor and creating peaks or waves across your floor.

The Real Culprits Behind Buckled Floors

1. Water Damage and Flooding

This is the big one. I've responded to water damage calls in Doylestown, Ardmore, and Gladwyne where everything from burst pipes to dishwasher leaks caused floors to buckle within 24-48 hours.

Here's what happens: when water sits on or under your hardwood floor, the wood soaks it up like a sponge. In homes throughout Blue Bell and Ambler, I've seen finished basements flood during heavy rains, and by the time the homeowner realizes what's happening, the floors are already compromised.

The worst case I ever saw was in Yardley—a vacation home where the owners were gone for three weeks and didn't know their washing machine hose had burst. When they came home, the entire first floor had buckled so badly we had to replace everything.

2. High Humidity and Poor Ventilation

This one sneaks up on people. You don't need a catastrophic flood for floors to buckle—sometimes it's just sustained high humidity over months or years.

In older homes throughout Haverford and Narberth, I've seen this happen in rooms with poor air circulation. The humidity slowly works its way into the wood, and eventually, the floors give out. Same thing happens in Buckingham and Solebury township homes with crawl spaces that aren't properly sealed or ventilated.

Your hardwood floors are happiest when indoor humidity stays between 30-50%. When it creeps above 60% for extended periods—which happens a lot in our humid Pennsylvania summers—you're asking for trouble.

3. Improper Installation

I hate to say it, but sometimes buckling happens because the floors weren't installed correctly in the first place.

Wood needs room to expand and contract with seasonal changes. That's why proper installers leave an expansion gap around the perimeter of the room—usually about 3/4 inch—covered by your baseboards. I've been called to homes in Villanova and Rosemont where previous contractors skipped this step or didn't leave enough gap, and when summer humidity hit, the floors had nowhere to expand except up.

Another installation mistake? Not acclimating the wood before installation. Hardwood needs to sit in your home for at least 3-5 days before installation so it can adjust to your home's temperature and humidity. Skip this step, and you're gambling with thousands of dollars worth of flooring.

4. Subfloor Moisture Issues

Sometimes the problem isn't even the hardwood itself—it's what's underneath. I've worked on countless homes in Lower Merion and Cheltenham where moisture was wicking up through concrete slabs that didn't have proper moisture barriers.

In New Hope and Langhorne, where many homes have basements or are built on slabs, this is incredibly common. If there's groundwater or moisture vapor coming up through your foundation and you install hardwood directly over it without a proper vapor barrier, you're essentially setting up a moisture trap. The wood absorbs that moisture from below and—you guessed it—buckles.

5. Plumbing Leaks You Don't Know About

This is the sneaky one that drives homeowners crazy. I've been called to beautiful homes in Conshohocken and Lafayette Hill where floors buckled seemingly out of nowhere. After pulling up the flooring, we discover a slow leak from a pipe in the subfloor that's been dripping for months.

Same thing happens with leaking radiators in older homes throughout Jenkintown and Abington. These slow, hidden leaks are dangerous because by the time you see the buckling on the surface, the damage underneath is usually extensive.

What About Seasonal Changes?

Here's something I explain to almost every customer: some minor expansion and contraction is normal. Our Pennsylvania climate is tough on hardwood—we get humid, muggy summers and dry, heated winters. Your floors are going to move a little bit. That's not buckling.

Real buckling is dramatic. You'll see boards lifting, gaps opening up, and peaks forming across your floor. If you just notice your floorboards are slightly tighter in summer and have small gaps in winter, that's just wood doing what wood does.

Can Buckled Floors Be Fixed?

The answer every homeowner hates: it depends.

If we catch it early—like within a few days of water exposure—sometimes we can dry out the floors, remove some boards to relieve pressure, and reinstall them once everything dries. I've had success with this approach in Wynnewood and Huntingdon Valley homes where homeowners called us immediately after discovering water damage.

But if the buckling is severe, or if it's been happening over a long period due to chronic moisture issues, you're usually looking at floor replacement. The boards have been permanently deformed, and no amount of sanding or refinishing will make them flat again.

Before we do anything, though, we have to fix the source of the moisture. I've had customers in Warminster and Willow Grove who wanted to just replace the buckled boards without addressing the humidity problem or fixing the leaking pipe. That's just throwing money away—the new floors will buckle too.

How to Prevent Floor Buckling

After two decades in this business, here's my honest advice:

Control your indoor humidity. Get a hygrometer (they're like $15) and keep an eye on it. Run dehumidifiers in summer, especially in basements. In homes throughout Perkasie and Quakertown, I always recommend whole-house dehumidifiers if the basement has hardwood.

Address water issues immediately. If you have a leak, a flood, or even just a big spill, don't wait. Pull up area rugs, get fans going, and call a professional. The faster you dry things out, the better your chances of saving the floor.

Use proper vapor barriers. If you're installing hardwood in a basement or over a concrete slab anywhere from Lansdale to Chalfont, insist on a high-quality moisture barrier. Don't let anyone tell you it's optional—it's not.

Maintain your home's systems. Check for plumbing leaks regularly. Make sure your HVAC system is working properly. Keep gutters clean so water doesn't pool around your foundation. This stuff matters more than people think.

Hire experienced installers. I know I'm biased here, but proper installation really does make a difference. A good installer will acclimate your wood, leave proper expansion gaps, use the right fasteners for your subfloor type, and make sure moisture levels are appropriate before starting work.

The Bottom Line

Buckled hardwood floors are heartbreaking to see, especially in the gorgeous homes we work on throughout the Mainline and Bucks County. But here's the good news: they're usually preventable, and when they do happen, an experienced contractor can often help you understand your options and get your home back to beautiful.

If you're seeing signs of buckling—boards lifting, peaks forming, gaps opening up—don't wait. The longer moisture sits in your floors, the worse the damage gets. And if you're planning a new hardwood installation, make sure your contractor is taking moisture seriously from day one.

We've been serving homeowners throughout Montgomery County, Bucks County, and the Philadelphia metro area for over 20 years, and we've seen it all when it comes to hardwood flooring problems. Whether you need an assessment of existing damage, emergency water damage response, or just want a second opinion on an installation quote, we're here to help.

Because at the end of the day, your floors should be something you're proud of—not something you're worried about.

Need help with buckled floors or want to prevent moisture damage? Contact Cyclone Hardwood Floors, LLC for a professional assessment. We serve homeowners throughout Bucks and Montgomery Counties with honest advice and expert craftsmanship.