Vinyl core construction

You can find out most of what matters about a plank's core in about a minute, standing at a counter, with no specification sheet and nobody helping. Weight, flex, sound and the cut edge answer four different questions, and none of the four can be talked around by a sample tag.

Four things your hands can find out

1. Weight. Pick the board up first, before you look at the face. A dense mineral core is noticeably heavy for its size. A foamed core is lighter for the same plank. A flexible core with no rigid layer is lighter again.
2. Flex. Hold one end and let the other hang, then try to bow it gently along its length. Rigid cores resist and spring back. Flexible ones fold under their own weight and stay where you put them.
3. Sound. Tap the face with a knuckle. A dense core gives a short flat report. A foamed core sounds duller and deeper. Anything with a pad bonded to the back is muffled from the first tap.
4. The cut edge. Turn the board on its side under a light. The whole stack is visible there, and it is the most informative half inch on any sample.

Reading the cut edge

From the top down you will usually see a clear layer, a thin printed film, the core, then whatever is bonded underneath. The clear layer is the bright band at the very top. How much of it there is decides how long the floor survives, and that is the subject of the wear layer page. The printed film reads as a dark hairline. Everything below the hairline is core.

The core's own appearance tells you which family you are holding. A stone polymer core reads pale, uniform and chalky, a grey or off white with no visible structure in it. A foamed wood polymer core reads slightly warmer with a faintly cellular texture you can pick out if you get close. A flexible core reads as solid coloured vinyl straight through, often the same tone as the plank's back.

If there is a pad it is unmistakable: a distinct band of grey foam or brown cork below the core, and on most boards it stops short of the locking edges so the joint lands on core instead of on foam. That layer changes the sound test you just ran, which the attached pad page explains.

What the flex test does and does not separate

Flex sorts rigid from flexible cleanly, and that is worth knowing on its own, because it is the difference between a plank that bridges a small dip in the subfloor and one that follows the dip exactly. It is also the difference between a floor that can float and one that generally cannot.

What flex will not do is separate the two rigid families from each other. Both of them resist bending in a hand sample and neither gives you a useful reading. Weight and thickness together do that job instead: for the same plank size, the dense one is heavier and thinner and the foamed one is lighter and thicker. The consequences of that split, for stability, comfort, sound and dents, are the whole subject of the SPC page and the WPC page, and there is no reason to relitigate them here. The field test only tells you which one is in your hand, and the rest of the category sits on the luxury vinyl plank page.

What the sample cannot tell you

This is worth being blunt about, because a good hand test creates false confidence. A sample sits on a hard counter. Your floor will sit on a joist bay, a slab or an old vinyl floor, and how the finished assembly sounds and feels is a property of that whole sandwich rather than of the board you are holding.

• It cannot tell you whether the locking joint is any good, which takes two boards rather than one. That is on the click-lock page.
• It cannot tell you the thickness of the clear layer above the print with any accuracy. Eyeballing that band is how people talk themselves into the wrong specification.
• It cannot tell you whether the plank suits your subfloor, because nobody has looked at your subfloor yet.
• It cannot tell you how the floor reads across a whole room, because a sample is smaller than one board and a floor is hundreds of them.

Those last two are the reason the hand test is a filter rather than a decision. It narrows a wall of options down to a few worth carrying home, and then the room does the rest of the work.

What a showroom floor shows that a screen cannot

Weight has no photograph. Neither does flex, nor the sound of a knuckle on a board, nor the difference between one plank tapped alone and two tapped together. A product page can describe a core honestly and still settle nothing, because every one of the four tests above needs a hand on the material. That is why boards are on the floor at 15570 Veterans Memorial Pkwy rather than only in a gallery.

Come and pick them up. Flex them, tap them, turn them over and look at the edge. Then take the ones that survive that home and set them on the actual floor in the actual light, which is the only test left after the hand test is finished. Call 636-332-0654 first and the lines you have been looking at will be waiting on the counter.