I review roughly 200+ flooring installations a year for compliance. About 12% get flagged before they're signed off. And honestly—most of those issues could've been caught during installation with a simple checklist.
Here's the 7-point process I run on every Karndean job (glue-down, loose-lay, Korlok click—doesn't matter). If you follow this, you'll save yourself the kind of phone call I hate making: explaining why a $22,000 install needs a partial redo.
1. Subfloor Verification
I check subfloor moisture content before anything else. For Karndean LVT, the standard is max 75% RH for a calcium chloride test, or 5 lbs per 1000 sq ft per 24 hours. I've seen jobs where the installer assumed 'it felt dry'—turns out, moisture issues cost about $8,000 in rework on one project I audited in Q1 2024.
What I verify:
- Moisture test results (with date and location)
- Concrete slab age (minimum 60 days for new pours)
- Flatness: 3/16 inch in 10 feet or better
- Cracks or uneven grout lines patched and leveled
Note: Karndean's own installation guidelines require subfloor prep. I've rejected batch submissions where the prep wasn't documented. (Really should have flagged that sooner.)
2. Adhesive & Underlayment Specs
I assumed once that 'same specifications' meant identical results across glue-down brands. Didn't verify. Turned out each had slightly different open times and coverage rates.
I check for:
- Correct adhesive: Karndean K-500 or approved equivalent
- Coverage: typically 50-60 sq ft per gallon for trowel-on
- Open time adhered to (usually 5-20 minutes depending on temperature)
- Underlayment for Korlok click: maximum 2mm thickness, or call Karndean
- No double-sided tape or tackifiers for loose-lay (that's a common mistake)
3. Color & Design Consistency
I run a color check across the entire order using a Pantone reference. Industry standard tolerance is Delta E < 2 for brand-critical colors—like Karndean's Van Gogh or Knight Tile series. Delta E 2-4 is noticeable to trained observers; above 4 is visible to most people. (Pantone Color Matching System guidelines)
What I look for:
- Batch-to-batch match: same color from different cartons
- Print registration: patterns line up within planks/tiles
- No more than 5% variation across the install floor
- Sheen consistency: matte vs gloss variation
Dodged a bullet on a project last year where the installer used planks from two different production runs. The difference was subtle—maybe a Delta E of 3—but in a showroom? Obvious. We swapped those planks before anyone noticed.
4. Installation Pattern & Layout
For herringbone and basketweave patterns (common in Karndean Art Select), I verify the layout sequence against the approved plan. A 10% offset minimum is standard for plank installations to avoid H-joints.
Checkpoints:
- Pattern alignment within ±1/16 inch
- End joints offset by at least 6 inches in adjacent rows
- No planks narrower than 6 inches at walls or transitions
- Herringbone angle consistent (usually 45 or 90 degrees)
5. Seam & Joint Quality
I run a fingernail test along seams. If I feel a catch, it's flagged.
Standards I use:
- Seam gaps less than 0.5mm (about the thickness of a credit card)
- No raised edges or lipping greater than 0.3mm
- Heat-welded seams (if specified) are flush within 0.1mm
- No adhesive bleed-through at seams (this ruins the visual)
Part of me wants to be lenient on seams—they're finicky. Another part knows that a bad seam catches dirt and looks terrible in six months. I compromise with a tolerance of 0.3mm; most installers hit 0.1-0.2mm.
6. Transition & Trim Work
Transitions are where I see the most errors. A bad transition ruins an otherwise perfect floor.
I check:
- Transition strips aligned within ±1/8 inch
- No sharp edges or exposed fasteners
- Expansion gaps at walls: 1/4 inch for cold-applied, 1/8 inch for loose-lay
- Reducer strips match floor height within 1/16 inch
Learned never to assume the transition strip will match after a batch arrived that looked nothing like what we approved. Now every contract includes a sample submission requirement.
7. Final Clean & Protection
This step gets skipped more than it should, especially on tight deadlines. But a floor that's scratched during final cleanup isn't a floor any inspector will sign off on.
Checklist:
- All adhesive residues cleaned (use Karndean floor cleaner, not generic)
- Floor protected with rosin paper or Ram Board for 48 hours after final pass
- No heavy furniture or foot traffic for minimum 24 hours (glue-down) or 12 hours (loose-lay)
- HVAC system running at 65-85°F for 72 hours post-install
Things I Wish I'd Known
- Color variation is normal in LVT (it's designed that way). But if it looks like a patchwork, something's off.
- Don't trust the 'same batch' label. I once had two cartons from the same batch with sheen differences. Always spot-check.
- If you're using a floor care kit afterward, make sure it's Karndean's. Generic products can dull the finish.
So glad I built this checklist after my third mistake. Almost went without one—would have cost us an estimated $14,000 in potential rework over the last year. (Note to self: keep refining this.)
