Think of weatherstripping as the silent bouncer between your cozy living room and the big, wild world outside. Its job is to keep the wind, rain, and bugs at bay—kind of like sealing the lid on a Tupperware to keep leftovers fresh. But over time, that seal can wear out. Honestly, it’s easy to overlook, but a damaged strip can turn your door into a revolving door for cold air, moisture, and noise. Let me walk you through why this happens, what it means, and what you can do about it.
What Is Weatherstripping, And Why Does It Matter?
Before we talk about *why* exterior door weatherstripping cracks and deteriorates, let’s get clear on what it is. Weatherstripping is the long, flexible strip—usually rubber, foam, or vinyl—that lines the edges of your door. Its main job is pretty simple: block outside air, moisture, and pests from getting in where the door meets the frame. Manufacturers like JELD-WEN or Masonite use weatherstripping in pretty much all their exterior doors, sometimes built into the frame and sometimes added later.
Here’s the thing—good weatherstripping forms a snug seal every time you shut your door. Over time, though, that perfect fit can fade. If there’s a gap or the material gets brittle, cold drafts, dust, water, and even noise start slipping in. Not only does this make your home less comfortable, but it can also send your energy bills through the roof. So, weatherstripping might seem basic, but it’s essential for a cozy, quiet house.
You might be surprised how much of a difference a small rubber strip can make. If you’ve ever replaced old weatherstripping and noticed things suddenly feel warmer, it’s not your imagination. That strip has a big job—and when it starts cracking or peeling, it’s time to pay attention.
Main Reasons Exterior Door Weatherstripping Cracks And Fails
Let me explain—weatherstripping isn’t meant to last forever. Several things can speed up its decline. The most common culprit is simply *old age*. Rubber and vinyl naturally get brittle and lose their springiness after years of getting squished every time you open and close the door.
But here’s what really does a number on weatherstripping:
- Sun Exposure – UV rays break down rubber and plastic. If your door faces south or west, sun damage happens even faster.
- Temperature Swings – Going from freezing cold to blazing hot (think midwinter mornings and summer afternoons) makes materials expand and shrink. This constant flexing eventually leads to cracking.
- Moisture & Humidity – Rain, condensation, and even regular cleaning can weaken adhesives or cause some foams to rot.
- Frequent Use – If you’re constantly opening and slamming the same door, the weatherstripping wears out faster from all that movement.
Honestly, even if you take good care of your door, no weatherstripping lasts forever. The higher quality strips from trusted brands like Therma-Tru or Masonite may last longer, but they’ll still eventually show signs of age. Pay attention to spots that get direct sun or heavy use, because those are the spots most likely to crack first.
Types Of Weatherstripping And How They Hold Up
You might be wondering if all weatherstripping breaks down the same way. The answer is: not really. Let me break it down:
- Foam Tape – Usually the cheapest and quickest to stick on. It’s soft, so it compresses well around gaps, but it’s also the first to wear out. Sun and moisture practically eat it for breakfast.
- Rubber or Vinyl Bulb/Tube – This is what you’ll find in most newer doors from brands like JELD-WEN. It’s a bit tougher. Still, UV light and constant squishing eventually make it hard and brittle.
- Felt – Old-school stuff, mostly for interior doors. It’s not weatherproof, so outdoors, it goes moldy or flattens out fast.
- Metal With Rubber Insert – More common on commercial doors or custom upgrades. The metal holds up, but the rubber insert can still crack or shrink over time.
If you’re thinking about replacing some cracked strips, it’s smart to weigh your options. Some universal weatherstripping can work in almost any door, but a brand-specific replacement from, say, Masonite or Therma-Tru, might fit better and last longer. Either way, remember that no material is truly forever when it’s battling sunlight and weather every day.
How To Spot Early Signs Of Weatherstripping Deterioration
You don’t need to be a home repair expert to spot when your exterior door weatherstripping is cracking and deteriorating. Honestly, the signs are usually right there—if you know what to look for.
Here’s what you might see:
- Visible Cracks Or Gaps – Take a close look at the strip when the door’s open. If you see splits, missing chunks, or big gaps, it’s time for action.
- Peeling Or Flaking – Sometimes the strip will start crumbling at the ends, or you’ll find rubber dust near the threshold.
- Loose Or Detached Strips – If the weatherstripping pulls away when you press it, that usually means the adhesive’s failed (or the strip’s shrunk).
- Drafts And Temperature Swings – If you can feel a cold draft or notice heat escaping around the door, that’s your weatherstripping waving the white flag.
It’s easy to brush off these clues, especially if they start small. But if you notice any of them, it’s much better to fix things sooner. A quick visual check once every few months—especially after a tough season—can save you money and hassle.
What Happens If You Ignore Cracked Or Old Weatherstripping?
Neglecting cracking and deteriorating weatherstripping doesn’t just make things a little drafty. It can snowball into bigger problems. Here’s why you shouldn’t let that little strip fall apart:
- Energy Waste – When your door’s not sealed, your heating and cooling have to work overtime to keep things comfortable. That means higher energy bills—sometimes by 10% or more, depending on the gap.
- Water Damage – Water sneaking in around bad strips can soak your floors or even slip into the walls. Over time, that leads to mold, rot, or warped wood. Not fun.
- Pest Problems – Cracked strips are an open invitation for bugs, spiders, and even mice to squeeze inside. If you’ve found more critters than usual, check those seals.
- Reduced Comfort And Noise Control – Besides cold drafts, you’ll likely hear more outdoor noise, too. Good weatherstripping helps keep things quiet and peaceful.
Let me put it this way: fixing weatherstripping is a tiny job compared to what happens if you let it fail for too long. Even if you’re busy, setting aside a little time now saves you way more hassle (and cash) in the long run.
Can You Repair Or Do You Need To Replace The Weatherstripping?
You might be tempted to squeeze a little more life out of that weatherstripping, but here’s the honest truth: once it’s cracking or falling apart, repairs usually won’t last. Weatherstripping is designed to compress and bounce back, and when it loses that spring, patching it is like trying to glue a dried-out sponge back together.
Still, there *are* a couple of quick fixes if you’re really in a bind:
- Temporary Sealants – Clear caulk or weatherproof tape can buy you a little time if you’ve only got a small gap.
- Reattaching Loose Sections – If the adhesive’s failed but the strip’s still squishy, a bit of strong glue sometimes works. Just don’t expect miracles.
But honestly, for most folks and most doors, it’s smarter to just replace weatherstripping when you see cracking and deterioration. You can find universal kits at any hardware store (think Frost King or M-D Building Products), or order a brand-specific strip for companies like JELD-WEN if you want a perfect fit. Swapping out weatherstripping is usually a 15–30 minute job, and you don’t need any fancy tools.
How To Replace Exterior Door Weatherstripping Step-By-Step
Ready to tackle that annoying draft? Here’s a simple step-by-step for replacing most standard weatherstripping:
- Remove The Old Strip – Open the door and gently pull the cracked weatherstripping free. Some strips slide out, others peel off. If there’s stubborn adhesive, use a putty knife for gentle prying.
- Clean The Surface – Grab a damp cloth and clear away dust, old glue, and any stuck-on bits. For extra-sticky messes, rubbing alcohol works well.
- Measure And Cut The New Strip – Measure each edge of the door frame and snip your new weatherstripping to fit. Angle the ends for a tight corner fit.
- Attach The New Weatherstripping – For adhesive types, peel off the backing and press firmly along the frame. For press-in vinyl strips, slide or snap them into the groove by hand. Check the instructions for your specific brand if you’re not sure.
- Test The Seal – Close the door and see how it feels. You want a firm seal without slamming the door shut. If the fit’s too tight or loose, adjust as needed.
Most folks can finish this task in less than an hour—even total beginners. If your brand uses a specialty strip or built-in insert (like some Masonite or Therma-Tru models), check your manual or search for the exact replacement online to make sure you’ve got the right part.
How To Prevent Premature Weatherstripping Deterioration
After you’ve fixed the problem, you’ll probably want your new weatherstripping to last as long as possible. Here’s what I’ve learned about keeping it in good shape:
- Keep It Clean – Every few months, wipe down the weatherstripping with a damp cloth to remove dirt and dust.
- Lubricate Occasionally – For rubber or vinyl strips, a light rub with silicone spray or talcum powder helps stop sticking and cracking. Just don’t overdo it!
- Watch For Damage – After extreme weather, take a quick peek to spot any problems early.
- Minimize Sun Exposure – If possible, use a door awning or shade to block out harsh afternoon sun. UV is the number-one villain in cracking and drying out weatherstripping.
Remember, even the best weatherstripping eventually wears out. Most brands (including big names like JELD-WEN) recommend a checkup at least once a year. Preventive care goes a long way, especially if your door faces harsh weather.
The bottom line: treat weatherstripping like a key part of your home—not just a throwaway detail. Catching problems early keeps your home warmer, drier, and a lot more comfortable.
Wrapping It All Up
Cracked and deteriorating weatherstripping on your exterior door isn’t just an eyesore—it’s a silent invitation for drafts, water, and critters to waltz right in. Whether you’ve got a classic wooden door or a modern Masonite steel entry, that strip needs attention now and then.
By knowing why weatherstripping fails—sun, age, and repeated use—plus how to spot and replace it, you’ll keep your home sealed tight without breaking a sweat. A little time, a trusty replacement kit, and some regular checkups will go a long way. If you’ve been ignoring those cracks, there’s no better moment than now to fix them and keep things cozy for the long haul.
