If you're planning a frameless shower door next to Karndean vinyl plank flooring, here's the short version: the transition zone matters more than the floor itself.
I learned this the expensive way. In my first year of handling bathroom renovations (2017), I specified a beautiful Karndean Van Gogh collection—a warm oak herringbone pattern—for a master ensuite with a glass-walled walk-in shower. Looked incredible in the render. The reality was a different story.
The problem wasn't the flooring. Karndean LVP is genuinely good at handling moisture for a vinyl product. The problem was where the frameless shower door's bottom sweep met the floor. Three months in, the edge of the plank nearest the door started showing signs of swelling at the seam. Not catastrophic, but noticeable enough that the homeowner called me on it.
Cost to fix: roughly $890, including removing the affected planks, replacing underlayment in that zone, and reinstalling. Plus a 1-week delay while the new planks acclimated. The homeowner was understanding, but I wasn't.
That's when I created our pre-install checklist for glass shower enclosures adjacent to LVT. I've since applied it to about 30 similar projects—and caught potential issues in 7 of them before installation. Here's what I wish someone had told me in 2017.
The Surprising Vulnerability
Most people assume the risk is water seeping through the vinyl. It's not. Karndean's rigid core and welded seams are quite resistant. The real vulnerability is water wicking laterally under the plank edge through the gap between the door sweep and the floor.
Frameless shower doors, by design, have a small gap at the bottom—typically 3-8mm depending on the sweep system. Even a well-installed sweep can't stop 100% of splashes. Over time, that moisture finds the seam between planks where the click-lock mechanism meets. And that's where the trouble starts.
The specific issue I encountered was with the Korlok click system on a loose-lay installation. The locking mechanism is strong, but it's not waterproof. Standing water against the seam, day after day, eventually compromised the edge. No surprise in hindsight—but nobody warned me at the time.
What Works: The Threshold Solution
After that mistake, I started using a shallow transition strip—about 3-5cm wide, matching the floor color—as a physical barrier between the shower door sweep and the Karndean planks. It's not about aesthetics (though it can look clean), it's about creating a break in the water path.
For Karndean's glue-down installations, which I now prefer for bathroom zones, I also add an extra bead of the manufacturer-recommended adhesive along the first row of planks nearest the shower. The adhesive creates a seal that prevents lateral wicking. Since adopting this method, I've had zero edge swelling incidents—touch wood.
Two other adjustments made a difference:
- Door sweep selection: Not all sweeps are equal. The ones with a continuous vinyl magnetic strip seal significantly better than brush-style sweeps. They're slightly more expensive (maybe $40-60 more) but worth it.
- Weekly visual check: I now include this in my handover notes. Takes 30 seconds—just look at the seam where the door meets the floor. If you see any discoloration or lifting, address it immediately.
"The mistake cost $890 and a week of delays. The fix cost $60 and 2 hours of labor. Should have done it right the first time."
A Common Misconception About 'Waterproof' Flooring
I hear this a lot: "But Karndean is waterproof, right? So why worry?"
This was true 10 years ago when expectations were lower. Today's LVT is more water-resistant than ever, but the term 'waterproof' gets over-interpreted. What it means is the core won't swell like MDF or particle board when exposed to moisture. It doesn't mean the locking mechanisms or seams are immune to prolonged standing water.
Think of it this way: a rain jacket is waterproof. But if you leave it submerged in a pool for weeks, the seams will eventually fail. Same concept.
The distinction matters because I've seen homeowners skip the threshold, skip the adhesive bead, skip the regular check—based on that 'waterproof' assumption. And it works fine for 6-12 months. But bathrooms are high-use, high-humidity environments. Over years, the accumulation matters.
The One Thing I'd Tell My 2017 Self
If I could go back and redo that first bathroom project, the single change I'd make isn't about the flooring quality or the door brand. It's this: treat the transition zone as a maintenance item, not a one-time install.
Frameless shower doors are beautiful. Karndean LVP is a solid choice for bathrooms. But the interface between them needs active management. A 30-second check every few weeks. A sweep inspection when you notice the door getting harder to slide. A quick re-caulk of the threshold strip if it starts lifting.
This approach has worked for us across maybe 20 post-2017 projects. But I can only speak to Australian residential bathrooms with standard shower sizes and daily use. If you're dealing with commercial bathrooms, high-traffic wet areas, or oversized shower enclosures, the calculus might be different. Commercial-grade sweeps and heavier thresholds would be my starting point.
The bottom line: Karndean is a great product. Don't let one improper interface scare you off. Just don't assume it's set-and-forget next to a glass shower enclosure. Plan for the seam, and you'll be fine.
