Laminate vs vinyl plank for a basement

Almost every version of this question gets answered by describing the planks — what the core is made of, whether it swells, how it handles a spilled drink. That is not what decides a basement, and you can prove it from the documents the two products ship with.

Both floors publish a moisture limit for the concrete underneath them, in the same units, measured with the same two ASTM test methods. The limits are different. So the honest form of the question is not “which is better down there” — it is “what does my slab actually read, and which of these two numbers does it come in under.” One afternoon with a test kit answers it.

Everything below was read out of the manufacturers’ own installation instructions in July 2026, and each document is linked at the foot of the page.

The same company publishes two different ceilings

Mohawk makes both a laminate line and a rigid vinyl line, which makes it the cleanest comparison available — same technical services department, same address on the letterhead, two sets of numbers.

Requirement for the slab	Laminate (Pergo, Mohawk RevWood)	Rigid vinyl (Mohawk SolidTech Plus)
Calcium chloride, ASTM F1869	≤ 5 lb/1,000 ft²/24 hr	≤ 8 lb/1,000 ft²/24 hr
In-situ probe, ASTM F2170	under 80% RH	under 90% RH
Slab pH	not specified	must be between 5.0 and 9.0
Newly poured slab	Mohawk RevWood: 1 week per 3/8 in of thickness up to 1-1/2 in, twice as long above that	must cure at least 90 days
Wood subfloor moisture	12% maximum	14% maximum
Polyethylene over a slab	Pergo requires a 6-mil vapor barrier under all its products on concrete	required over the ground in a crawl space; not called for over a slab
Sump pump in that floor	Pergo: not permitted anywhere on that level	not named in the prohibited-use list
Floor drain in the room	Pergo: not permitted	not named in the prohibited-use list

Read the top two rows and the gap is 8 against 5, and 90 against 80 — a vapour-emission ceiling sixty per cent higher, and ten points of relative humidity. Mohawk’s earlier SolidTech guidelines, revised October 2018, give the same pair from the other direction: “less than 90% relative humidity (RH test, ASTM F2170) or less than 8 lbs moisture vapor emission rate.”

The important thing about that gap is that it only runs one way. Every slab dry enough for laminate is dry enough for the vinyl. The reverse is not true, and the band between the two ceilings is exactly where basement slabs tend to sit — a floor that reads 6 lb, or 85% RH, has failed one product’s instructions and passed the other’s. If your slab lands in that band the choice has already been made for you, and no amount of reading about core construction changes it.

Test first, because it costs less than the flooring

Two methods are named, and they are not interchangeable. ASTM F1869 is the anhydrous calcium chloride test, and Mohawk spells out what its result means in plain words: “not to exceed five pounds of water vapor being emitted from 1000 square feet of flooring over a period of 24 hours.” ASTM F2170 is the in-situ probe test, which reports the relative humidity measured inside the slab rather than the vapour coming off its surface. A slab can be handed either verdict, and the instructions above accept either.

Mohawk’s SolidTech Plus instructions tell you where to put them: “at locations around exterior doorways, near walls containing plumbing, near foundation walls and in the center of the room.” Those are the four places a basement slab is wettest, and averaging one lucky reading from the middle of the floor is how people talk themselves into a floor that fails in year two.

Pergo’s guide adds the caveat that matters most in a basement, and it is worth quoting because it undermines the test you just paid for: “During a dry season, you may find that you get an acceptable moisture reading even if other job site conditions are not acceptable… you must be sure that your job site conditions as well as your moisture readings are acceptable year around.” A reading taken in February is a reading about February.

The sump pump clause exists on only one of the two sheets

This is the single most basement-specific rule either manufacturer publishes, and it is far broader than people expect. Pergo:

“should there be a floor at a below grade level or a on-grade level concrete slab in the home and a sump pump is located in that below-grade level flooring or in the on-grade level slab, then Pergo flooring cannot be installed anywhere on that floor.”

Not “not in the utility room” — anywhere on that level. The guide gives its own reasoning a paragraph earlier: high water tables “necessitate the use of sump pumps to pump water that is flowing beneath a concrete floor,” and a pump running is evidence that water is moving under the slab whatever a spot reading says. The same guide rules out any room with a floor drain.

The SolidTech Plus instructions carry a prohibited-use list of their own — “outside areas, saunas, seasonal porches, camping trailers, boats, RVs, lanais, rooms that are prone to flooding, or rooms or homes that are not temperature-controlled.” A sump pump does not appear in it, and neither does a floor drain. That is a statement about what these two documents say, and it is checkable in about ninety seconds from the links below; it is not a claim that a pump is harmless.

“Waterproof” is a claim about the plank, not about the slab

Both categories are now sold as waterproof, and the word does no work here at all. Mohawk states the limit of it plainly in the SolidTech Plus instructions:

“Mohawk SolidTech Plus is a waterproof floating floor, but it should not be used to seal an existing floor from moisture. It cannot inhibit the growth of mold or prevent structural problems associated with or caused by flooding, excessive moisture, alkalis in the subfloor, or conditions arising from hydrostatic pressure.”

The laminate side makes the same point by simply not moving. STAINMASTER’s instruction sheet is titled Waterproof Laminate Flooring Installation Instructions, and it still requires calcium chloride values “≤ 5 lbs/1000ft²/24-hr or <80% RH with an in situ probe,” and it still says the product “should not be installed over any floor with a sump pump or in a room with a floor drain.” Waterproofing the top face of a plank does not change what the concrete is allowed to emit into the back of it.

What does not decide this, and what it costs to get wrong

Quantity does not decide it. Both products are sold by the carton, both carton coverages vary by style rather than by category, and both want a waste allowance. Pergo’s laminate guide and the SolidTech Plus instructions land on an identical pair of figures — 10% added to the area on a square layout, 15% where the planks run diagonally — so the allowance is not a tiebreaker either. If you are pricing the two options against each other, convert to whole cartons before you compare, because that is the unit you actually buy; the laminate flooring calculator does the carton rounding and shows the spare you end up owning.

What does decide it is a number you can get for the price of a test kit. If the slab reads under 5 lb and under 80% RH, and there is no pump or drain on that level, both products’ own instructions permit the floor and you can choose on looks, price and how the room sounds underfoot. If it reads between the two ceilings, only one of them is installable as published. If it fails both, the answer is neither, and Pergo’s guide points at the outside of the house for the fix — soil sloping away from the foundation “at least 1/2 inch per foot for at least 10 feet,” gutters and downspouts discharging clear of it.

Installing over a slab that failed the test does not void a hypothetical warranty in some abstract sense. It fails in a specific, visible way, months later, and the material is not recoverable when it does.